Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Ctors](https://developer.android.com/reference/java/util/TreeMap#pubctors) \| [Methods](https://developer.android.com/reference/java/util/TreeMap#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/java/util/TreeMap#inhmethods) # TreeMap ` public class TreeMap ` ` ` ` extends https://developer.android.com/reference/java/util/AbstractMap ` ` implements https://developer.android.com/reference/java/lang/Cloneable, https://developer.android.com/reference/java/util/NavigableMap, https://developer.android.com/reference/java/io/Serializable ` |---|---|---| | [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||| | ↳ | [java.util.AbstractMap](https://developer.android.com/reference/java/util/AbstractMap)\ || | | ↳ | java.util.TreeMap\ |
*** ** * ** *** A Red-Black tree based `https://developer.android.com/reference/java/util/NavigableMap` implementation. The map is sorted according to the [natural ordering](https://developer.android.com/reference/java/lang/Comparable) of its keys, or by a `https://developer.android.com/reference/java/util/Comparator` provided at map creation time, depending on which constructor is used. This implementation provides guaranteed log(n) time cost for the `containsKey`, `get`, `put` and `remove` operations. Algorithms are adaptations of those in Cormen, Leiserson, and Rivest's *Introduction to Algorithms*. Note that the ordering maintained by a tree map, like any sorted map, and whether or not an explicit comparator is provided, must be *consistent with `equals`* if this sorted map is to correctly implement the `Map` interface. (See `Comparable` or `Comparator` for a precise definition of *consistent with equals* .) This is so because the `Map` interface is defined in terms of the `equals` operation, but a sorted map performs all key comparisons using its `compareTo` (or `compare`) method, so two keys that are deemed equal by this method are, from the standpoint of the sorted map, equal. The behavior of a sorted map *is* well-defined even if its ordering is inconsistent with `equals`; it just fails to obey the general contract of the `Map` interface. **Note that this implementation is not synchronized.** If multiple threads access a map concurrently, and at least one of the threads modifies the map structurally, it *must* be synchronized externally. (A structural modification is any operation that adds or deletes one or more mappings; merely changing the value associated with an existing key is not a structural modification.) This is typically accomplished by synchronizing on some object that naturally encapsulates the map. If no such object exists, the map should be "wrapped" using the `https://developer.android.com/reference/java/util/Collections#synchronizedSortedMap(java.util.SortedMap)` method. This is best done at creation time, to prevent accidental unsynchronized access to the map: ``` SortedMap m = Collections.synchronizedSortedMap(new TreeMap(...)); ``` The iterators returned by the `iterator` method of the collections returned by all of this class's "collection view methods" are *fail-fast* : if the map is structurally modified at any time after the iterator is created, in any way except through the iterator's own `remove` method, the iterator will throw a `https://developer.android.com/reference/java/util/ConcurrentModificationException`. Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future. Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent modification. Fail-fast iterators throw `ConcurrentModificationException` on a best-effort basis. Therefore, it would be wrong to write a program that depended on this exception for its correctness: *the fail-fast behavior of iterators should be used only to detect bugs.* The methods `https://developer.android.com/reference/java/util/TreeMap#ceilingEntry(K)`, `https://developer.android.com/reference/java/util/TreeMap#firstEntry()`, `https://developer.android.com/reference/java/util/TreeMap#floorEntry(K)`, `https://developer.android.com/reference/java/util/TreeMap#higherEntry(K)`, `https://developer.android.com/reference/java/util/TreeMap#lastEntry()`, `https://developer.android.com/reference/java/util/TreeMap#lowerEntry(K)`, `https://developer.android.com/reference/java/util/TreeMap#pollFirstEntry()`, and `https://developer.android.com/reference/java/util/TreeMap#pollLastEntry()` return `https://developer.android.com/reference/java/util/Map.Entry` instances that represent snapshots of mappings as of the time of the call. They do *not* support mutation of the underlying map via the optional `https://developer.android.com/reference/java/util/Map.Entry#setValue(V)` method. The `https://developer.android.com/reference/java/util/TreeMap#putFirst(K,%20V)` and `https://developer.android.com/reference/java/util/TreeMap#putLast(K,%20V)` methods of this class throw `UnsupportedOperationException`. The encounter order of mappings is determined by the comparison method; therefore, explicit positioning is not supported. This class is a member of the [Java Collections Framework](https://reference/java/util/package-summary.html#CollectionsFramework). **See also:** - `https://developer.android.com/reference/java/util/Map` - `https://developer.android.com/reference/java/util/HashMap` - `https://developer.android.com/reference/java/util/Hashtable` - `https://developer.android.com/reference/java/lang/Comparable` - `https://developer.android.com/reference/java/util/Comparator` - `https://developer.android.com/reference/java/util/Collection` ## Summary | ### Public constructors || |---|---| | ` https://developer.android.com/reference/java/util/TreeMap#TreeMap()() ` Constructs a new, empty tree map, using the natural ordering of its keys. | | ` https://developer.android.com/reference/java/util/TreeMap#TreeMap(java.util.Comparator)(https://developer.android.com/reference/java/util/Comparator comparator) ` Constructs a new, empty tree map, ordered according to the given comparator. | | ` https://developer.android.com/reference/java/util/TreeMap#TreeMap(java.util.Map)(https://developer.android.com/reference/java/util/Map m) ` Constructs a new tree map containing the same mappings as the given map, ordered according to the *natural ordering* of its keys. | | ` https://developer.android.com/reference/java/util/TreeMap#TreeMap(java.util.SortedMap)(https://developer.android.com/reference/java/util/SortedMap m) ` Constructs a new tree map containing the same mappings and using the same ordering as the specified sorted map. | | ### Public methods || |---|---| | ` https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/TreeMap#ceilingEntry(K)(K key) ` Returns a key-value mapping associated with the least key greater than or equal to the given key, or `null` if there is no such key. | | ` K` | ` https://developer.android.com/reference/java/util/TreeMap#ceilingKey(K)(K key) ` Returns the least key greater than or equal to the given key, or `null` if there is no such key. | | ` void` | ` https://developer.android.com/reference/java/util/TreeMap#clear()() ` Removes all of the mappings from this map. | | ` https://developer.android.com/reference/java/lang/Object` | ` https://developer.android.com/reference/java/util/TreeMap#clone()() ` Returns a shallow copy of this `TreeMap` instance. | | ` https://developer.android.com/reference/java/util/Comparator` | ` https://developer.android.com/reference/java/util/TreeMap#comparator()() ` Returns the comparator used to order the keys in this map, or `null` if this map uses the [natural ordering](https://developer.android.com/reference/java/lang/Comparable) of its keys. | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#compute(K,%20java.util.function.BiFunction)(K key, https://developer.android.com/reference/java/util/function/BiFunction remappingFunction) ` Attempts to compute a mapping for the specified key and its current mapped value, or `null` if there is no current mapping (optional operation). This method will, on a best-effort basis, throw a `https://developer.android.com/reference/java/util/ConcurrentModificationException` if it is detected that the remapping function modifies this map during computation. | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#computeIfAbsent(K,%20java.util.function.Function)(K key, https://developer.android.com/reference/java/util/function/Function mappingFunction) ` If the specified key is not already associated with a value (or is mapped to `null`), attempts to compute its value using the given mapping function and enters it into this map unless `null` (optional operation). This method will, on a best-effort basis, throw a `https://developer.android.com/reference/java/util/ConcurrentModificationException` if it is detected that the mapping function modifies this map during computation. | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#computeIfPresent(K,%20java.util.function.BiFunction)(K key, https://developer.android.com/reference/java/util/function/BiFunction remappingFunction) ` If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value (optional operation). This method will, on a best-effort basis, throw a `https://developer.android.com/reference/java/util/ConcurrentModificationException` if it is detected that the remapping function modifies this map during computation. | | ` boolean` | ` https://developer.android.com/reference/java/util/TreeMap#containsKey(java.lang.Object)(https://developer.android.com/reference/java/lang/Object key) ` Returns `true` if this map contains a mapping for the specified key. | | ` boolean` | ` https://developer.android.com/reference/java/util/TreeMap#containsValue(java.lang.Object)(https://developer.android.com/reference/java/lang/Object value) ` Returns `true` if this map maps one or more keys to the specified value. | | ` https://developer.android.com/reference/java/util/NavigableSet` | ` https://developer.android.com/reference/java/util/TreeMap#descendingKeySet()() ` Returns a reverse order `https://developer.android.com/reference/java/util/NavigableSet` view of the keys contained in this map. | | ` https://developer.android.com/reference/java/util/NavigableMap` | ` https://developer.android.com/reference/java/util/TreeMap#descendingMap()() ` Returns a reverse order view of the mappings contained in this map. | | ` https://developer.android.com/reference/java/util/Set>` | ` https://developer.android.com/reference/java/util/TreeMap#entrySet()() ` Returns a `https://developer.android.com/reference/java/util/Set` view of the mappings contained in this map. | | ` https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/TreeMap#firstEntry()() ` Returns a key-value mapping associated with the least key in this map, or `null` if the map is empty. | | ` K` | ` https://developer.android.com/reference/java/util/TreeMap#firstKey()() ` Returns the first (lowest) key currently in this map. | | ` https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/TreeMap#floorEntry(K)(K key) ` Returns a key-value mapping associated with the greatest key less than or equal to the given key, or `null` if there is no such key. | | ` K` | ` https://developer.android.com/reference/java/util/TreeMap#floorKey(K)(K key) ` Returns the greatest key less than or equal to the given key, or `null` if there is no such key. | | ` void` | ` https://developer.android.com/reference/java/util/TreeMap#forEach(java.util.function.BiConsumer)(https://developer.android.com/reference/java/util/function/BiConsumer action) ` Performs the given action for each entry in this map until all entries have been processed or the action throws an exception. | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#get(java.lang.Object)(https://developer.android.com/reference/java/lang/Object key) ` Returns the value to which the specified key is mapped, or `null` if this map contains no mapping for the key. | | ` https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/TreeMap#headMap(K)(K toKey) ` Returns a view of the portion of this map whose keys are strictly less than `toKey`. Equivalent to `headMap(toKey, false)`. | | ` https://developer.android.com/reference/java/util/NavigableMap` | ` https://developer.android.com/reference/java/util/TreeMap#headMap(K,%20boolean)(K toKey, boolean inclusive) ` Returns a view of the portion of this map whose keys are less than (or equal to, if `inclusive` is true) `toKey`. | | ` https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/TreeMap#higherEntry(K)(K key) ` Returns a key-value mapping associated with the least key strictly greater than the given key, or `null` if there is no such key. | | ` K` | ` https://developer.android.com/reference/java/util/TreeMap#higherKey(K)(K key) ` Returns the least key strictly greater than the given key, or `null` if there is no such key. | | ` https://developer.android.com/reference/java/util/Set` | ` https://developer.android.com/reference/java/util/TreeMap#keySet()() ` Returns a `https://developer.android.com/reference/java/util/Set` view of the keys contained in this map. | | ` https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/TreeMap#lastEntry()() ` Returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty. | | ` K` | ` https://developer.android.com/reference/java/util/TreeMap#lastKey()() ` Returns the last (highest) key currently in this map. | | ` https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/TreeMap#lowerEntry(K)(K key) ` Returns a key-value mapping associated with the greatest key strictly less than the given key, or `null` if there is no such key. | | ` K` | ` https://developer.android.com/reference/java/util/TreeMap#lowerKey(K)(K key) ` Returns the greatest key strictly less than the given key, or `null` if there is no such key. | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#merge(K,%20V,%20java.util.function.BiFunction)(K key, V value, https://developer.android.com/reference/java/util/function/BiFunction remappingFunction) ` If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value (optional operation). This method will, on a best-effort basis, throw a `https://developer.android.com/reference/java/util/ConcurrentModificationException` if it is detected that the remapping function modifies this map during computation. | | ` https://developer.android.com/reference/java/util/NavigableSet` | ` https://developer.android.com/reference/java/util/TreeMap#navigableKeySet()() ` Returns a `https://developer.android.com/reference/java/util/NavigableSet` view of the keys contained in this map. | | ` https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/TreeMap#pollFirstEntry()() ` Removes and returns a key-value mapping associated with the least key in this map, or `null` if the map is empty (optional operation). | | ` https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/TreeMap#pollLastEntry()() ` Removes and returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty (optional operation). | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#put(K,%20V)(K key, V value) ` Associates the specified value with the specified key in this map. | | ` void` | ` https://developer.android.com/reference/java/util/TreeMap#putAll(java.util.Map)(https://developer.android.com/reference/java/util/Map map) ` Copies all of the mappings from the specified map to this map. | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#putFirst(K,%20V)(K k, V v) ` Throws `UnsupportedOperationException`. | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#putIfAbsent(K,%20V)(K key, V value) ` If the specified key is not already associated with a value (or is mapped to `null`) associates it with the given value and returns `null`, else returns the current value (optional operation). | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#putLast(K,%20V)(K k, V v) ` Throws `UnsupportedOperationException`. | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#remove(java.lang.Object)(https://developer.android.com/reference/java/lang/Object key) ` Removes the mapping for this key from this TreeMap if present. | | ` boolean` | ` https://developer.android.com/reference/java/util/TreeMap#replace(K,%20V,%20V)(K key, V oldValue, V newValue) ` Replaces the entry for the specified key only if currently mapped to the specified value (optional operation). | | ` V` | ` https://developer.android.com/reference/java/util/TreeMap#replace(K,%20V)(K key, V value) ` Replaces the entry for the specified key only if it is currently mapped to some value (optional operation). | | ` void` | ` https://developer.android.com/reference/java/util/TreeMap#replaceAll(java.util.function.BiFunction)(https://developer.android.com/reference/java/util/function/BiFunction function) ` Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception (optional operation). | | ` int` | ` https://developer.android.com/reference/java/util/TreeMap#size()() ` Returns the number of key-value mappings in this map. | | ` https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/TreeMap#subMap(K,%20K)(K fromKey, K toKey) ` Returns a view of the portion of this map whose keys range from `fromKey`, inclusive, to `toKey`, exclusive. Equivalent to `subMap(fromKey, true, toKey, false)`. | | ` https://developer.android.com/reference/java/util/NavigableMap` | ` https://developer.android.com/reference/java/util/TreeMap#subMap(K,%20boolean,%20K,%20boolean)(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) ` Returns a view of the portion of this map whose keys range from `fromKey` to `toKey`. | | ` https://developer.android.com/reference/java/util/NavigableMap` | ` https://developer.android.com/reference/java/util/TreeMap#tailMap(K,%20boolean)(K fromKey, boolean inclusive) ` Returns a view of the portion of this map whose keys are greater than (or equal to, if `inclusive` is true) `fromKey`. | | ` https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/TreeMap#tailMap(K)(K fromKey) ` Returns a view of the portion of this map whose keys are greater than or equal to `fromKey`. Equivalent to `tailMap(fromKey, true)`. | | ` https://developer.android.com/reference/java/util/Collection` | ` https://developer.android.com/reference/java/util/TreeMap#values()() ` Returns a `https://developer.android.com/reference/java/util/Collection` view of the values contained in this map. | | ### Inherited methods | |---|---| | From class ` https://developer.android.com/reference/java/util/AbstractMap ` |---|---| | ` void` | ` https://developer.android.com/reference/java/util/AbstractMap#clear()() ` Removes all of the mappings from this map (optional operation). | | ` https://developer.android.com/reference/java/lang/Object` | ` https://developer.android.com/reference/java/util/AbstractMap#clone()() ` Returns a shallow copy of this `AbstractMap` instance: the keys and values themselves are not cloned. | | ` boolean` | ` https://developer.android.com/reference/java/util/AbstractMap#containsKey(java.lang.Object)(https://developer.android.com/reference/java/lang/Object key) ` Returns `true` if this map contains a mapping for the specified key. | | ` boolean` | ` https://developer.android.com/reference/java/util/AbstractMap#containsValue(java.lang.Object)(https://developer.android.com/reference/java/lang/Object value) ` Returns `true` if this map maps one or more keys to the specified value. | | ` abstract https://developer.android.com/reference/java/util/Set>` | ` https://developer.android.com/reference/java/util/AbstractMap#entrySet()() ` Returns a `https://developer.android.com/reference/java/util/Set` view of the mappings contained in this map. | | ` boolean` | ` https://developer.android.com/reference/java/util/AbstractMap#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object o) ` Compares the specified object with this map for equality. | | ` V` | ` https://developer.android.com/reference/java/util/AbstractMap#get(java.lang.Object)(https://developer.android.com/reference/java/lang/Object key) ` Returns the value to which the specified key is mapped, or `null` if this map contains no mapping for the key. | | ` int` | ` https://developer.android.com/reference/java/util/AbstractMap#hashCode()() ` Returns the hash code value for this map. | | ` boolean` | ` https://developer.android.com/reference/java/util/AbstractMap#isEmpty()() ` Returns `true` if this map contains no key-value mappings. | | ` https://developer.android.com/reference/java/util/Set` | ` https://developer.android.com/reference/java/util/AbstractMap#keySet()() ` Returns a `https://developer.android.com/reference/java/util/Set` view of the keys contained in this map. | | ` V` | ` https://developer.android.com/reference/java/util/AbstractMap#put(K,%20V)(K key, V value) ` Associates the specified value with the specified key in this map (optional operation). | | ` void` | ` https://developer.android.com/reference/java/util/AbstractMap#putAll(java.util.Map)(https://developer.android.com/reference/java/util/Map m) ` Copies all of the mappings from the specified map to this map (optional operation). | | ` V` | ` https://developer.android.com/reference/java/util/AbstractMap#remove(java.lang.Object)(https://developer.android.com/reference/java/lang/Object key) ` Removes the mapping for a key from this map if it is present (optional operation). | | ` int` | ` https://developer.android.com/reference/java/util/AbstractMap#size()() ` Returns the number of key-value mappings in this map. | | ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/util/AbstractMap#toString()() ` Returns a string representation of this map. | | ` https://developer.android.com/reference/java/util/Collection` | ` https://developer.android.com/reference/java/util/AbstractMap#values()() ` Returns a `https://developer.android.com/reference/java/util/Collection` view of the values contained in this map. | || | From class ` https://developer.android.com/reference/java/lang/Object ` |---|---| | ` https://developer.android.com/reference/java/lang/Object` | ` https://developer.android.com/reference/java/lang/Object#clone()() ` Creates and returns a copy of this object. | | ` boolean` | ` https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) ` Indicates whether some other object is "equal to" this one. | | ` void` | ` https://developer.android.com/reference/java/lang/Object#finalize()() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ` final https://developer.android.com/reference/java/lang/Class` | ` https://developer.android.com/reference/java/lang/Object#getClass()() ` Returns the runtime class of this `Object`. | | ` int` | ` https://developer.android.com/reference/java/lang/Object#hashCode()() ` Returns a hash code value for the object. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#notify()() ` Wakes up a single thread that is waiting on this object's monitor. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#notifyAll()() ` Wakes up all threads that are waiting on this object's monitor. | | ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/lang/Object#toString()() ` Returns a string representation of the object. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#wait(long,%20int)(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#wait(long)(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#wait()() ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*. | || | From interface ` https://developer.android.com/reference/java/util/Map ` |---|---| | ` abstract void` | ` https://developer.android.com/reference/java/util/Map#clear()() ` Removes all of the mappings from this map (optional operation). | | ` default V` | ` https://developer.android.com/reference/java/util/Map#compute(K,%20java.util.function.BiFunction)(K key, https://developer.android.com/reference/java/util/function/BiFunction remappingFunction) ` Attempts to compute a mapping for the specified key and its current mapped value, or `null` if there is no current mapping (optional operation). | | ` default V` | ` https://developer.android.com/reference/java/util/Map#computeIfAbsent(K,%20java.util.function.Function)(K key, https://developer.android.com/reference/java/util/function/Function mappingFunction) ` If the specified key is not already associated with a value (or is mapped to `null`), attempts to compute its value using the given mapping function and enters it into this map unless `null` (optional operation). | | ` default V` | ` https://developer.android.com/reference/java/util/Map#computeIfPresent(K,%20java.util.function.BiFunction)(K key, https://developer.android.com/reference/java/util/function/BiFunction remappingFunction) ` If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value (optional operation). | | ` abstract boolean` | ` https://developer.android.com/reference/java/util/Map#containsKey(java.lang.Object)(https://developer.android.com/reference/java/lang/Object key) ` Returns `true` if this map contains a mapping for the specified key. | | ` abstract boolean` | ` https://developer.android.com/reference/java/util/Map#containsValue(java.lang.Object)(https://developer.android.com/reference/java/lang/Object value) ` Returns `true` if this map maps one or more keys to the specified value. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#copyOf(java.util.Map)(https://developer.android.com/reference/java/util/Map map) ` Returns an [unmodifiable Map](https://developer.android.com/reference/java/util/TreeMap#unmodifiable) containing the entries of the given Map. | | ` static https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/Map#entry(K,%20V)(K k, V v) ` Returns an unmodifiable `https://developer.android.com/reference/java/util/Map.Entry` containing the given key and value. | | ` abstract https://developer.android.com/reference/java/util/Set>` | ` https://developer.android.com/reference/java/util/Map#entrySet()() ` Returns a `https://developer.android.com/reference/java/util/Set` view of the mappings contained in this map. | | ` abstract boolean` | ` https://developer.android.com/reference/java/util/Map#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object o) ` Compares the specified object with this map for equality. | | ` default void` | ` https://developer.android.com/reference/java/util/Map#forEach(java.util.function.BiConsumer)(https://developer.android.com/reference/java/util/function/BiConsumer action) ` Performs the given action for each entry in this map until all entries have been processed or the action throws an exception. | | ` abstract V` | ` https://developer.android.com/reference/java/util/Map#get(java.lang.Object)(https://developer.android.com/reference/java/lang/Object key) ` Returns the value to which the specified key is mapped, or `null` if this map contains no mapping for the key. | | ` default V` | ` https://developer.android.com/reference/java/util/Map#getOrDefault(java.lang.Object,%20V)(https://developer.android.com/reference/java/lang/Object key, V defaultValue) ` Returns the value to which the specified key is mapped, or `defaultValue` if this map contains no mapping for the key. | | ` abstract int` | ` https://developer.android.com/reference/java/util/Map#hashCode()() ` Returns the hash code value for this map. | | ` abstract boolean` | ` https://developer.android.com/reference/java/util/Map#isEmpty()() ` Returns `true` if this map contains no key-value mappings. | | ` abstract https://developer.android.com/reference/java/util/Set` | ` https://developer.android.com/reference/java/util/Map#keySet()() ` Returns a `https://developer.android.com/reference/java/util/Set` view of the keys contained in this map. | | ` default V` | ` https://developer.android.com/reference/java/util/Map#merge(K,%20V,%20java.util.function.BiFunction)(K key, V value, https://developer.android.com/reference/java/util/function/BiFunction remappingFunction) ` If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value (optional operation). | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V)(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) ` Returns an unmodifiable map containing five mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V,%20K,%20V,%20K,%20V,%20K,%20V)(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) ` Returns an unmodifiable map containing four mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V)(K k1, V v1) ` Returns an unmodifiable map containing a single mapping. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V)(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7, K k8, V v8) ` Returns an unmodifiable map containing eight mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V,%20K,%20V)(K k1, V v1, K k2, V v2) ` Returns an unmodifiable map containing two mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V,%20K,%20V,%20K,%20V)(K k1, V v1, K k2, V v2, K k3, V v3) ` Returns an unmodifiable map containing three mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of()() ` Returns an unmodifiable map containing zero mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V)(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7, K k8, V v8, K k9, V v9) ` Returns an unmodifiable map containing nine mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V)(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6) ` Returns an unmodifiable map containing six mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V)(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7) ` Returns an unmodifiable map containing seven mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#of(K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V,%20K,%20V)(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7, K k8, V v8, K k9, V v9, K k10, V v10) ` Returns an unmodifiable map containing ten mappings. | | ` static https://developer.android.com/reference/java/util/Map` | ` https://developer.android.com/reference/java/util/Map#ofEntries(java.util.Map.Entry[])(https://developer.android.com/reference/java/util/Map.Entry entries) ` Returns an unmodifiable map containing keys and values extracted from the given entries. | | ` abstract V` | ` https://developer.android.com/reference/java/util/Map#put(K,%20V)(K key, V value) ` Associates the specified value with the specified key in this map (optional operation). | | ` abstract void` | ` https://developer.android.com/reference/java/util/Map#putAll(java.util.Map)(https://developer.android.com/reference/java/util/Map m) ` Copies all of the mappings from the specified map to this map (optional operation). | | ` default V` | ` https://developer.android.com/reference/java/util/Map#putIfAbsent(K,%20V)(K key, V value) ` If the specified key is not already associated with a value (or is mapped to `null`) associates it with the given value and returns `null`, else returns the current value (optional operation). | | ` default boolean` | ` https://developer.android.com/reference/java/util/Map#remove(java.lang.Object,%20java.lang.Object)(https://developer.android.com/reference/java/lang/Object key, https://developer.android.com/reference/java/lang/Object value) ` Removes the entry for the specified key only if it is currently mapped to the specified value (optional operation). | | ` abstract V` | ` https://developer.android.com/reference/java/util/Map#remove(java.lang.Object)(https://developer.android.com/reference/java/lang/Object key) ` Removes the mapping for a key from this map if it is present (optional operation). | | ` default boolean` | ` https://developer.android.com/reference/java/util/Map#replace(K,%20V,%20V)(K key, V oldValue, V newValue) ` Replaces the entry for the specified key only if currently mapped to the specified value (optional operation). | | ` default V` | ` https://developer.android.com/reference/java/util/Map#replace(K,%20V)(K key, V value) ` Replaces the entry for the specified key only if it is currently mapped to some value (optional operation). | | ` default void` | ` https://developer.android.com/reference/java/util/Map#replaceAll(java.util.function.BiFunction)(https://developer.android.com/reference/java/util/function/BiFunction function) ` Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception (optional operation). | | ` abstract int` | ` https://developer.android.com/reference/java/util/Map#size()() ` Returns the number of key-value mappings in this map. | | ` abstract https://developer.android.com/reference/java/util/Collection` | ` https://developer.android.com/reference/java/util/Map#values()() ` Returns a `https://developer.android.com/reference/java/util/Collection` view of the values contained in this map. | || | From interface ` https://developer.android.com/reference/java/util/NavigableMap ` |---|---| | ` abstract https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/NavigableMap#ceilingEntry(K)(K key) ` Returns a key-value mapping associated with the least key greater than or equal to the given key, or `null` if there is no such key. | | ` abstract K` | ` https://developer.android.com/reference/java/util/NavigableMap#ceilingKey(K)(K key) ` Returns the least key greater than or equal to the given key, or `null` if there is no such key. | | ` abstract https://developer.android.com/reference/java/util/NavigableSet` | ` https://developer.android.com/reference/java/util/NavigableMap#descendingKeySet()() ` Returns a reverse order `https://developer.android.com/reference/java/util/NavigableSet` view of the keys contained in this map. | | ` abstract https://developer.android.com/reference/java/util/NavigableMap` | ` https://developer.android.com/reference/java/util/NavigableMap#descendingMap()() ` Returns a reverse order view of the mappings contained in this map. | | ` abstract https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/NavigableMap#firstEntry()() ` Returns a key-value mapping associated with the least key in this map, or `null` if the map is empty. | | ` abstract https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/NavigableMap#floorEntry(K)(K key) ` Returns a key-value mapping associated with the greatest key less than or equal to the given key, or `null` if there is no such key. | | ` abstract K` | ` https://developer.android.com/reference/java/util/NavigableMap#floorKey(K)(K key) ` Returns the greatest key less than or equal to the given key, or `null` if there is no such key. | | ` abstract https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/NavigableMap#headMap(K)(K toKey) ` Returns a view of the portion of this map whose keys are strictly less than `toKey`. Equivalent to `headMap(toKey, false)`. | | ` abstract https://developer.android.com/reference/java/util/NavigableMap` | ` https://developer.android.com/reference/java/util/NavigableMap#headMap(K,%20boolean)(K toKey, boolean inclusive) ` Returns a view of the portion of this map whose keys are less than (or equal to, if `inclusive` is true) `toKey`. | | ` abstract https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/NavigableMap#higherEntry(K)(K key) ` Returns a key-value mapping associated with the least key strictly greater than the given key, or `null` if there is no such key. | | ` abstract K` | ` https://developer.android.com/reference/java/util/NavigableMap#higherKey(K)(K key) ` Returns the least key strictly greater than the given key, or `null` if there is no such key. | | ` abstract https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/NavigableMap#lastEntry()() ` Returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty. | | ` abstract https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/NavigableMap#lowerEntry(K)(K key) ` Returns a key-value mapping associated with the greatest key strictly less than the given key, or `null` if there is no such key. | | ` abstract K` | ` https://developer.android.com/reference/java/util/NavigableMap#lowerKey(K)(K key) ` Returns the greatest key strictly less than the given key, or `null` if there is no such key. | | ` abstract https://developer.android.com/reference/java/util/NavigableSet` | ` https://developer.android.com/reference/java/util/NavigableMap#navigableKeySet()() ` Returns a `https://developer.android.com/reference/java/util/NavigableSet` view of the keys contained in this map. | | ` abstract https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/NavigableMap#pollFirstEntry()() ` Removes and returns a key-value mapping associated with the least key in this map, or `null` if the map is empty (optional operation). | | ` abstract https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/NavigableMap#pollLastEntry()() ` Removes and returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty (optional operation). | | ` default https://developer.android.com/reference/java/util/NavigableMap` | ` https://developer.android.com/reference/java/util/NavigableMap#reversed()() ` Returns a reverse-ordered [view](https://developer.android.com/reference/java/util/Collection#view) of this map. This method is equivalent to `https://developer.android.com/reference/java/util/NavigableMap#descendingMap()`. | | ` abstract https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/NavigableMap#subMap(K,%20K)(K fromKey, K toKey) ` Returns a view of the portion of this map whose keys range from `fromKey`, inclusive, to `toKey`, exclusive. Equivalent to `subMap(fromKey, true, toKey, false)`. | | ` abstract https://developer.android.com/reference/java/util/NavigableMap` | ` https://developer.android.com/reference/java/util/NavigableMap#subMap(K,%20boolean,%20K,%20boolean)(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) ` Returns a view of the portion of this map whose keys range from `fromKey` to `toKey`. | | ` abstract https://developer.android.com/reference/java/util/NavigableMap` | ` https://developer.android.com/reference/java/util/NavigableMap#tailMap(K,%20boolean)(K fromKey, boolean inclusive) ` Returns a view of the portion of this map whose keys are greater than (or equal to, if `inclusive` is true) `fromKey`. | | ` abstract https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/NavigableMap#tailMap(K)(K fromKey) ` Returns a view of the portion of this map whose keys are greater than or equal to `fromKey`. Equivalent to `tailMap(fromKey, true)`. | || | From interface ` https://developer.android.com/reference/java/util/SortedMap ` |---|---| | ` abstract https://developer.android.com/reference/java/util/Comparator` | ` https://developer.android.com/reference/java/util/SortedMap#comparator()() ` Returns the comparator used to order the keys in this map, or `null` if this map uses the [natural ordering](https://developer.android.com/reference/java/lang/Comparable) of its keys. | | ` abstract https://developer.android.com/reference/java/util/Set>` | ` https://developer.android.com/reference/java/util/SortedMap#entrySet()() ` Returns a `https://developer.android.com/reference/java/util/Set` view of the mappings contained in this map. | | ` abstract K` | ` https://developer.android.com/reference/java/util/SortedMap#firstKey()() ` Returns the first (lowest) key currently in this map. | | ` abstract https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/SortedMap#headMap(K)(K toKey) ` Returns a view of the portion of this map whose keys are strictly less than `toKey`. | | ` abstract https://developer.android.com/reference/java/util/Set` | ` https://developer.android.com/reference/java/util/SortedMap#keySet()() ` Returns a `https://developer.android.com/reference/java/util/Set` view of the keys contained in this map. | | ` abstract K` | ` https://developer.android.com/reference/java/util/SortedMap#lastKey()() ` Returns the last (highest) key currently in this map. | | ` default V` | ` https://developer.android.com/reference/java/util/SortedMap#putFirst(K,%20V)(K k, V v) ` Throws `UnsupportedOperationException`. | | ` default V` | ` https://developer.android.com/reference/java/util/SortedMap#putLast(K,%20V)(K k, V v) ` Throws `UnsupportedOperationException`. | | ` default https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/SortedMap#reversed()() ` Returns a reverse-ordered [view](https://developer.android.com/reference/java/util/Collection#view) of this map. | | ` abstract https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/SortedMap#subMap(K,%20K)(K fromKey, K toKey) ` Returns a view of the portion of this map whose keys range from `fromKey`, inclusive, to `toKey`, exclusive. | | ` abstract https://developer.android.com/reference/java/util/SortedMap` | ` https://developer.android.com/reference/java/util/SortedMap#tailMap(K)(K fromKey) ` Returns a view of the portion of this map whose keys are greater than or equal to `fromKey`. | | ` abstract https://developer.android.com/reference/java/util/Collection` | ` https://developer.android.com/reference/java/util/SortedMap#values()() ` Returns a `https://developer.android.com/reference/java/util/Collection` view of the values contained in this map. | || | From interface ` https://developer.android.com/reference/java/util/SequencedMap ` |---|---| | ` default https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/SequencedMap#firstEntry()() ` Returns the first key-value mapping in this map, or `null` if the map is empty. | | ` default https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/SequencedMap#lastEntry()() ` Returns the last key-value mapping in this map, or `null` if the map is empty. | | ` default https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/SequencedMap#pollFirstEntry()() ` Removes and returns the first key-value mapping in this map, or `null` if the map is empty (optional operation). | | ` default https://developer.android.com/reference/java/util/Map.Entry` | ` https://developer.android.com/reference/java/util/SequencedMap#pollLastEntry()() ` Removes and returns the last key-value mapping in this map, or `null` if the map is empty (optional operation). | | ` default V` | ` https://developer.android.com/reference/java/util/SequencedMap#putFirst(K,%20V)(K k, V v) ` Inserts the given mapping into the map if it is not already present, or replaces the value of a mapping if it is already present (optional operation). | | ` default V` | ` https://developer.android.com/reference/java/util/SequencedMap#putLast(K,%20V)(K k, V v) ` Inserts the given mapping into the map if it is not already present, or replaces the value of a mapping if it is already present (optional operation). | | ` abstract https://developer.android.com/reference/java/util/SequencedMap` | ` https://developer.android.com/reference/java/util/SequencedMap#reversed()() ` Returns a reverse-ordered [view](https://developer.android.com/reference/java/util/Collection#view) of this map. | | ` default https://developer.android.com/reference/java/util/SequencedSet>` | ` https://developer.android.com/reference/java/util/SequencedMap#sequencedEntrySet()() ` Returns a `SequencedSet` view of this map's `https://developer.android.com/reference/java/util/Map#entrySet()`. | | ` default https://developer.android.com/reference/java/util/SequencedSet` | ` https://developer.android.com/reference/java/util/SequencedMap#sequencedKeySet()() ` Returns a `SequencedSet` view of this map's `https://developer.android.com/reference/java/util/Map#keySet()`. | | ` default https://developer.android.com/reference/java/util/SequencedCollection` | ` https://developer.android.com/reference/java/util/SequencedMap#sequencedValues()() ` Returns a `SequencedCollection` view of this map's `https://developer.android.com/reference/java/util/Map#values()` collection. | || ## Public constructors ### TreeMap Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public TreeMap () ``` Constructs a new, empty tree map, using the natural ordering of its keys. All keys inserted into the map must implement the `https://developer.android.com/reference/java/lang/Comparable` interface. Furthermore, all such keys must be *mutually comparable* : `k1.compareTo(k2)` must not throw a `ClassCastException` for any keys `k1` and `k2` in the map. If the user attempts to put a key into the map that violates this constraint (for example, the user attempts to put a string key into a map whose keys are integers), the `put(Object key, Object value)` call will throw a `ClassCastException`.
### TreeMap Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public TreeMap (Comparator comparator) ``` Constructs a new, empty tree map, ordered according to the given comparator. All keys inserted into the map must be *mutually comparable* by the given comparator: `comparator.compare(k1, k2)` must not throw a `ClassCastException` for any keys `k1` and `k2` in the map. If the user attempts to put a key into the map that violates this constraint, the `put(Object key, Object value)` call will throw a `ClassCastException`.
| Parameters || |---|---| | `comparator` | `Comparator`: the comparator that will be used to order this map. If `null`, the [natural ordering](https://developer.android.com/reference/java/lang/Comparable) of the keys will be used.
| ### TreeMap Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public TreeMap (Map m) ``` Constructs a new tree map containing the same mappings as the given map, ordered according to the *natural ordering* of its keys. All keys inserted into the new map must implement the `https://developer.android.com/reference/java/lang/Comparable` interface. Furthermore, all such keys must be *mutually comparable* : `k1.compareTo(k2)` must not throw a `ClassCastException` for any keys `k1` and `k2` in the map. This method runs in n\*log(n) time.
| Parameters || |---|---| | `m` | `Map`: the map whose mappings are to be placed in this map
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | if the keys in m are not `https://developer.android.com/reference/java/lang/Comparable`, or are not mutually comparable | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified map is null | ### TreeMap Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public TreeMap (SortedMap m) ``` Constructs a new tree map containing the same mappings and using the same ordering as the specified sorted map. This method runs in linear time.
| Parameters || |---|---| | `m` | `SortedMap`: the sorted map whose mappings are to be placed in this map, and whose comparator is to be used to sort this map
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified map is null | ## Public methods ### ceilingEntry Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Entry ceilingEntry (K key) ``` Returns a key-value mapping associated with the least key greater than or equal to the given key, or `null` if there is no such key.
| Parameters || |---|---| | `key` | `K`: the key
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/Map.Entry` | an entry with the least key greater than or equal to `key`, or `null` if there is no such key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### ceilingKey Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public K ceilingKey (K key) ``` Returns the least key greater than or equal to the given key, or `null` if there is no such key.
| Parameters || |---|---| | `key` | `K`: the key
| | Returns || |---|---| | `K` | the least key greater than or equal to `key`, or `null` if there is no such key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### clear Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public void clear () ``` Removes all of the mappings from this map. The map will be empty after this call returns.
### clone Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Object clone () ``` Returns a shallow copy of this `TreeMap` instance. (The keys and values themselves are not cloned.)
| Returns || |---|---| | `https://developer.android.com/reference/java/lang/Object` | a shallow copy of this map
| ### comparator Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Comparator comparator () ``` Returns the comparator used to order the keys in this map, or `null` if this map uses the [natural ordering](https://developer.android.com/reference/java/lang/Comparable) of its keys.
| Returns || |---|---| | `https://developer.android.com/reference/java/util/Comparator` | the comparator used to order the keys in this map, or `null` if this map uses the natural ordering of its keys
| ### compute Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V compute (K key, BiFunction remappingFunction) ``` Attempts to compute a mapping for the specified key and its current mapped value, or `null` if there is no current mapping (optional operation). For example, to either create or append a `String` msg to a value mapping: map.compute(key, (k, v) -> (v == null) ? msg : v.concat(msg)) (Method `https://developer.android.com/reference/java/util/Map#merge(K,%20V,%20java.util.function.BiFunction)` is often simpler to use for such purposes.) If the remapping function returns `null`, the mapping is removed (or remains absent if initially absent). If the remapping function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged. The remapping function should not modify this map during computation. This method will, on a best-effort basis, throw a `https://developer.android.com/reference/java/util/ConcurrentModificationException` if it is detected that the remapping function modifies this map during computation.
| Parameters || |---|---| | `key` | `K`: key with which the specified value is to be associated
| | `remappingFunction` | `BiFunction`: the remapping function to compute a value
| | Returns || |---|---| | `V` | the new value associated with the specified key, or null if none
| | Throws || |---|---| | `https://developer.android.com/reference/java/util/ConcurrentModificationException` | if it is detected that the remapping function modified this map | ### computeIfAbsent Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V computeIfAbsent (K key, Function mappingFunction) ``` If the specified key is not already associated with a value (or is mapped to `null`), attempts to compute its value using the given mapping function and enters it into this map unless `null` (optional operation). If the mapping function returns `null`, no mapping is recorded. If the mapping function itself throws an (unchecked) exception, the exception is rethrown, and no mapping is recorded. The most common usage is to construct a new object serving as an initial mapped value or memoized result, as in: map.computeIfAbsent(key, k -> new Value(f(k))); Or to implement a multi-value map, `Map>`, supporting multiple values per key: map.computeIfAbsent(key, k -> new HashSet()).add(v); The mapping function should not modify this map during computation. This method will, on a best-effort basis, throw a `https://developer.android.com/reference/java/util/ConcurrentModificationException` if it is detected that the mapping function modifies this map during computation.
| Parameters || |---|---| | `key` | `K`: key with which the specified value is to be associated
| | `mappingFunction` | `Function`: the mapping function to compute a value
| | Returns || |---|---| | `V` | the current (existing or computed) value associated with the specified key, or null if the computed value is null
| | Throws || |---|---| | `https://developer.android.com/reference/java/util/ConcurrentModificationException` | if it is detected that the mapping function modified this map | ### computeIfPresent Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V computeIfPresent (K key, BiFunction remappingFunction) ``` If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value (optional operation). If the remapping function returns `null`, the mapping is removed. If the remapping function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged. The remapping function should not modify this map during computation. This method will, on a best-effort basis, throw a `https://developer.android.com/reference/java/util/ConcurrentModificationException` if it is detected that the remapping function modifies this map during computation.
| Parameters || |---|---| | `key` | `K`: key with which the specified value is to be associated
| | `remappingFunction` | `BiFunction`: the remapping function to compute a value
| | Returns || |---|---| | `V` | the new value associated with the specified key, or null if none
| | Throws || |---|---| | `https://developer.android.com/reference/java/util/ConcurrentModificationException` | if it is detected that the remapping function modified this map | ### containsKey Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public boolean containsKey (Object key) ``` Returns `true` if this map contains a mapping for the specified key.
| Parameters || |---|---| | `key` | `Object`: key whose presence in this map is to be tested
| | Returns || |---|---| | `boolean` | `true` if this map contains a mapping for the specified key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | if the specified key cannot be compared with the keys currently in the map | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### containsValue Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public boolean containsValue (Object value) ``` Returns `true` if this map maps one or more keys to the specified value. More formally, returns `true` if and only if this map contains at least one mapping to a value `v` such that `(value==null ? v==null : value.equals(v))`. This operation will probably require time linear in the map size for most implementations.
| Parameters || |---|---| | `value` | `Object`: value whose presence in this map is to be tested
| | Returns || |---|---| | `boolean` | `true` if a mapping to `value` exists; `false` otherwise
| ### descendingKeySet Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public NavigableSet descendingKeySet () ``` Returns a reverse order `https://developer.android.com/reference/java/util/NavigableSet` view of the keys contained in this map. The set's iterator returns the keys in descending order. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Set.remove`, `removeAll`, `retainAll`, and `clear` operations. It does not support the `add` or `addAll` operations.
| Returns || |---|---| | `https://developer.android.com/reference/java/util/NavigableSet` | a reverse order navigable set view of the keys in this map
| ### descendingMap Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public NavigableMap descendingMap () ``` Returns a reverse order view of the mappings contained in this map. The descending map is backed by this map, so changes to the map are reflected in the descending map, and vice-versa. If either map is modified while an iteration over a collection view of either map is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The returned map has an ordering equivalent to `https://developer.android.com/reference/java/util/Collections#reverseOrder(java.util.Comparator)``(comparator())`. The expression `m.descendingMap().descendingMap()` returns a view of `m` essentially equivalent to `m`.
| Returns || |---|---| | `https://developer.android.com/reference/java/util/NavigableMap` | a reverse order view of this map
| ### entrySet Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Set> entrySet () ``` Returns a `https://developer.android.com/reference/java/util/Set` view of the mappings contained in this map. The set's iterator returns the entries in ascending key order. The set's spliterator is *[late-binding](https://developer.android.com/reference/java/util/Spliterator#binding)* , *fail-fast* , and additionally reports `https://developer.android.com/reference/java/util/Spliterator#SORTED` and `https://developer.android.com/reference/java/util/Spliterator#ORDERED` with an encounter order that is ascending key order. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own `remove` operation, or through the `setValue` operation on a map entry returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Set.remove`, `removeAll`, `retainAll` and `clear` operations. It does not support the `add` or `addAll` operations.
| Returns || |---|---| | `https://developer.android.com/reference/java/util/Set>` | a set view of the mappings contained in this map
| ### firstEntry Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Entry firstEntry () ``` Returns a key-value mapping associated with the least key in this map, or `null` if the map is empty.
| Returns || |---|---| | `https://developer.android.com/reference/java/util/Map.Entry` | an entry with the least key, or `null` if this map is empty
| ### firstKey Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public K firstKey () ``` Returns the first (lowest) key currently in this map.
| Returns || |---|---| | `K` | the first (lowest) key currently in this map
| | Throws || |---|---| | `https://developer.android.com/reference/java/util/NoSuchElementException` | | ### floorEntry Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Entry floorEntry (K key) ``` Returns a key-value mapping associated with the greatest key less than or equal to the given key, or `null` if there is no such key.
| Parameters || |---|---| | `key` | `K`: the key
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/Map.Entry` | an entry with the greatest key less than or equal to `key`, or `null` if there is no such key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### floorKey Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public K floorKey (K key) ``` Returns the greatest key less than or equal to the given key, or `null` if there is no such key.
| Parameters || |---|---| | `key` | `K`: the key
| | Returns || |---|---| | `K` | the greatest key less than or equal to `key`, or `null` if there is no such key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### forEach Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public void forEach (BiConsumer action) ``` Performs the given action for each entry in this map until all entries have been processed or the action throws an exception. Unless otherwise specified by the implementing class, actions are performed in the order of entry set iteration (if an iteration order is specified.) Exceptions thrown by the action are relayed to the caller.
| Parameters || |---|---| | `action` | `BiConsumer`: The action to be performed for each entry
| ### get Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V get (Object key) ``` Returns the value to which the specified key is mapped, or `null` if this map contains no mapping for the key. More formally, if this map contains a mapping from a key `k` to a value `v` such that `key` compares equal to `k` according to the map's ordering, then this method returns `v`; otherwise it returns `null`. (There can be at most one such mapping.) A return value of `null` does not *necessarily* indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key to `null`. The `https://developer.android.com/reference/java/util/TreeMap#containsKey(java.lang.Object)` operation may be used to distinguish these two cases.
| Parameters || |---|---| | `key` | `Object`: the key whose associated value is to be returned
| | Returns || |---|---| | `V` | the value to which the specified key is mapped, or `null` if this map contains no mapping for the key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | if the specified key cannot be compared with the keys currently in the map | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### headMap Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public SortedMap headMap (K toKey) ``` Returns a view of the portion of this map whose keys are strictly less than `toKey`. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range. Equivalent to `headMap(toKey, false)`.
| Parameters || |---|---| | `toKey` | `K`: high endpoint (exclusive) of the keys in the returned map
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/SortedMap` | a view of the portion of this map whose keys are strictly less than `toKey`
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/IllegalArgumentException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if `toKey` is null and this map uses natural ordering, or its comparator does not permit null keys | ### headMap Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public NavigableMap headMap (K toKey, boolean inclusive) ``` Returns a view of the portion of this map whose keys are less than (or equal to, if `inclusive` is true) `toKey`. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range.
| Parameters || |---|---| | `toKey` | `K`: high endpoint of the keys in the returned map
| | `inclusive` | `boolean`: `true` if the high endpoint is to be included in the returned view
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/NavigableMap` | a view of the portion of this map whose keys are less than (or equal to, if `inclusive` is true) `toKey`
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/IllegalArgumentException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if `toKey` is null and this map uses natural ordering, or its comparator does not permit null keys | ### higherEntry Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Entry higherEntry (K key) ``` Returns a key-value mapping associated with the least key strictly greater than the given key, or `null` if there is no such key.
| Parameters || |---|---| | `key` | `K`: the key
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/Map.Entry` | an entry with the least key greater than `key`, or `null` if there is no such key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### higherKey Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public K higherKey (K key) ``` Returns the least key strictly greater than the given key, or `null` if there is no such key.
| Parameters || |---|---| | `key` | `K`: the key
| | Returns || |---|---| | `K` | the least key greater than `key`, or `null` if there is no such key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### keySet Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Set keySet () ``` Returns a `https://developer.android.com/reference/java/util/Set` view of the keys contained in this map. The set's iterator returns the keys in ascending order. The set's spliterator is *[late-binding](https://developer.android.com/reference/java/util/Spliterator#binding)* , *fail-fast* , and additionally reports `https://developer.android.com/reference/java/util/Spliterator#SORTED` and `https://developer.android.com/reference/java/util/Spliterator#ORDERED` with an encounter order that is ascending key order. The spliterator's comparator (see `https://developer.android.com/reference/java/util/Spliterator#getComparator()`) is `null` if the tree map's comparator (see `https://developer.android.com/reference/java/util/TreeMap#comparator()`) is `null`. Otherwise, the spliterator's comparator is the same as or imposes the same total ordering as the tree map's comparator. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Set.remove`, `removeAll`, `retainAll`, and `clear` operations. It does not support the `add` or `addAll` operations.
| Returns || |---|---| | `https://developer.android.com/reference/java/util/Set` | a set view of the keys contained in this map
| ### lastEntry Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Entry lastEntry () ``` Returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty.
| Returns || |---|---| | `https://developer.android.com/reference/java/util/Map.Entry` | an entry with the greatest key, or `null` if this map is empty
| ### lastKey Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public K lastKey () ``` Returns the last (highest) key currently in this map.
| Returns || |---|---| | `K` | the last (highest) key currently in this map
| | Throws || |---|---| | `https://developer.android.com/reference/java/util/NoSuchElementException` | | ### lowerEntry Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Entry lowerEntry (K key) ``` Returns a key-value mapping associated with the greatest key strictly less than the given key, or `null` if there is no such key.
| Parameters || |---|---| | `key` | `K`: the key
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/Map.Entry` | an entry with the greatest key less than `key`, or `null` if there is no such key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### lowerKey Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public K lowerKey (K key) ``` Returns the greatest key strictly less than the given key, or `null` if there is no such key.
| Parameters || |---|---| | `key` | `K`: the key
| | Returns || |---|---| | `K` | the greatest key less than `key`, or `null` if there is no such key
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### merge Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V merge (K key, V value, BiFunction remappingFunction) ``` If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value (optional operation). Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result is `null`. This method may be of use when combining multiple mapped values for a key. For example, to either create or append a `String msg` to a value mapping: map.merge(key, msg, String::concat) If the remapping function returns `null`, the mapping is removed. If the remapping function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged. The remapping function should not modify this map during computation. This method will, on a best-effort basis, throw a `https://developer.android.com/reference/java/util/ConcurrentModificationException` if it is detected that the remapping function modifies this map during computation.
| Parameters || |---|---| | `key` | `K`: key with which the resulting value is to be associated
| | `value` | `V`: the non-null value to be merged with the existing value associated with the key or, if no existing value or a null value is associated with the key, to be associated with the key
| | `remappingFunction` | `BiFunction`: the remapping function to recompute a value if present
| | Returns || |---|---| | `V` | the new value associated with the specified key, or null if no value is associated with the key
| | Throws || |---|---| | `https://developer.android.com/reference/java/util/ConcurrentModificationException` | if it is detected that the remapping function modified this map | ### navigableKeySet Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public NavigableSet navigableKeySet () ``` Returns a `https://developer.android.com/reference/java/util/NavigableSet` view of the keys contained in this map. The set's iterator returns the keys in ascending order. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Set.remove`, `removeAll`, `retainAll`, and `clear` operations. It does not support the `add` or `addAll` operations.
| Returns || |---|---| | `https://developer.android.com/reference/java/util/NavigableSet` | a navigable set view of the keys in this map
| ### pollFirstEntry Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Entry pollFirstEntry () ``` Removes and returns a key-value mapping associated with the least key in this map, or `null` if the map is empty (optional operation).
| Returns || |---|---| | `https://developer.android.com/reference/java/util/Map.Entry` | the removed first entry of this map, or `null` if this map is empty
| ### pollLastEntry Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Entry pollLastEntry () ``` Removes and returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty (optional operation).
| Returns || |---|---| | `https://developer.android.com/reference/java/util/Map.Entry` | the removed last entry of this map, or `null` if this map is empty
| ### put Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V put (K key, V value) ``` Associates the specified value with the specified key in this map. If the map previously contained a mapping for the key, the old value is replaced.
| Parameters || |---|---| | `key` | `K`: key with which the specified value is to be associated
| | `value` | `V`: value to be associated with the specified key
| | Returns || |---|---| | `V` | the previous value associated with `key`, or `null` if there was no mapping for `key`. (A `null` return can also indicate that the map previously associated `null` with `key`.)
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | if the specified key cannot be compared with the keys currently in the map | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### putAll Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public void putAll (Map map) ``` Copies all of the mappings from the specified map to this map. These mappings replace any mappings that this map had for any of the keys currently in the specified map.
| Parameters || |---|---| | `map` | `Map`: mappings to be stored in this map
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | if the class of a key or value in the specified map prevents it from being stored in this map | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified map is null or the specified map contains a null key and this map does not permit null keys | ### putFirst Added in [API level 35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V putFirst (K k, V v) ``` Throws `UnsupportedOperationException`. The encounter order induced by this map's comparison method determines the position of mappings, so explicit positioning is not supported.
| Parameters || |---|---| | `k` | `K`: the key
| | `v` | `V`: the value
| | Returns || |---|---| | `V` | the value previously associated with k, or null if none
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/UnsupportedOperationException` | always | ### putIfAbsent Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V putIfAbsent (K key, V value) ``` If the specified key is not already associated with a value (or is mapped to `null`) associates it with the given value and returns `null`, else returns the current value (optional operation).
| Parameters || |---|---| | `key` | `K`: key with which the specified value is to be associated
| | `value` | `V`: value to be associated with the specified key
| | Returns || |---|---| | `V` | the previous value associated with the specified key, or `null` if there was no mapping for the key. (A `null` return can also indicate that the map previously associated `null` with the key, if the implementation supports null values.)
| ### putLast Added in [API level 35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V putLast (K k, V v) ``` Throws `UnsupportedOperationException`. The encounter order induced by this map's comparison method determines the position of mappings, so explicit positioning is not supported.
| Parameters || |---|---| | `k` | `K`: the key
| | `v` | `V`: the value
| | Returns || |---|---| | `V` | the value previously associated with k, or null if none
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/UnsupportedOperationException` | always | ### remove Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V remove (Object key) ``` Removes the mapping for this key from this TreeMap if present.
| Parameters || |---|---| | `key` | `Object`: key for which mapping should be removed
| | Returns || |---|---| | `V` | the previous value associated with `key`, or `null` if there was no mapping for `key`. (A `null` return can also indicate that the map previously associated `null` with `key`.)
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | if the specified key cannot be compared with the keys currently in the map | | `https://developer.android.com/reference/java/lang/NullPointerException` | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys | ### replace Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public boolean replace (K key, V oldValue, V newValue) ``` Replaces the entry for the specified key only if currently mapped to the specified value (optional operation).
| Parameters || |---|---| | `key` | `K`: key with which the specified value is associated
| | `oldValue` | `V`: value expected to be associated with the specified key
| | `newValue` | `V`: value to be associated with the specified key
| | Returns || |---|---| | `boolean` | `true` if the value was replaced
| ### replace Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public V replace (K key, V value) ``` Replaces the entry for the specified key only if it is currently mapped to some value (optional operation).
| Parameters || |---|---| | `key` | `K`: key with which the specified value is associated
| | `value` | `V`: value to be associated with the specified key
| | Returns || |---|---| | `V` | the previous value associated with the specified key, or `null` if there was no mapping for the key. (A `null` return can also indicate that the map previously associated `null` with the key, if the implementation supports null values.)
| ### replaceAll Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public void replaceAll (BiFunction function) ``` Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception (optional operation). Exceptions thrown by the function are relayed to the caller.
| Parameters || |---|---| | `function` | `BiFunction`: the function to apply to each entry
| ### size Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int size () ``` Returns the number of key-value mappings in this map.
| Returns || |---|---| | `int` | the number of key-value mappings in this map
| ### subMap Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public SortedMap subMap (K fromKey, K toKey) ``` Returns a view of the portion of this map whose keys range from `fromKey`, inclusive, to `toKey`, exclusive. (If `fromKey` and `toKey` are equal, the returned map is empty.) The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range. Equivalent to `subMap(fromKey, true, toKey, false)`.
| Parameters || |---|---| | `fromKey` | `K`: low endpoint (inclusive) of the keys in the returned map
| | `toKey` | `K`: high endpoint (exclusive) of the keys in the returned map
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/SortedMap` | a view of the portion of this map whose keys range from `fromKey`, inclusive, to `toKey`, exclusive
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/IllegalArgumentException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if `fromKey` or `toKey` is null and this map uses natural ordering, or its comparator does not permit null keys | ### subMap Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public NavigableMap subMap (K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) ``` Returns a view of the portion of this map whose keys range from `fromKey` to `toKey`. If `fromKey` and `toKey` are equal, the returned map is empty unless `fromInclusive` and `toInclusive` are both true. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside of its range, or to construct a submap either of whose endpoints lie outside its range.
| Parameters || |---|---| | `fromKey` | `K`: low endpoint of the keys in the returned map
| | `fromInclusive` | `boolean`: `true` if the low endpoint is to be included in the returned view
| | `toKey` | `K`: high endpoint of the keys in the returned map
| | `toInclusive` | `boolean`: `true` if the high endpoint is to be included in the returned view
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/NavigableMap` | a view of the portion of this map whose keys range from `fromKey` to `toKey`
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/IllegalArgumentException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if `fromKey` or `toKey` is null and this map uses natural ordering, or its comparator does not permit null keys | ### tailMap Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public NavigableMap tailMap (K fromKey, boolean inclusive) ``` Returns a view of the portion of this map whose keys are greater than (or equal to, if `inclusive` is true) `fromKey`. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range.
| Parameters || |---|---| | `fromKey` | `K`: low endpoint of the keys in the returned map
| | `inclusive` | `boolean`: `true` if the low endpoint is to be included in the returned view
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/NavigableMap` | a view of the portion of this map whose keys are greater than (or equal to, if `inclusive` is true) `fromKey`
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/IllegalArgumentException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if `fromKey` is null and this map uses natural ordering, or its comparator does not permit null keys | ### tailMap Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public SortedMap tailMap (K fromKey) ``` Returns a view of the portion of this map whose keys are greater than or equal to `fromKey`. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range. Equivalent to `tailMap(fromKey, true)`.
| Parameters || |---|---| | `fromKey` | `K`: low endpoint (inclusive) of the keys in the returned map
| | Returns || |---|---| | `https://developer.android.com/reference/java/util/SortedMap` | a view of the portion of this map whose keys are greater than or equal to `fromKey`
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/ClassCastException` | | | `https://developer.android.com/reference/java/lang/IllegalArgumentException` | | | `https://developer.android.com/reference/java/lang/NullPointerException` | if `fromKey` is null and this map uses natural ordering, or its comparator does not permit null keys | ### values Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Collection values () ``` Returns a `https://developer.android.com/reference/java/util/Collection` view of the values contained in this map. The collection's iterator returns the values in ascending order of the corresponding keys. The collection's spliterator is *[late-binding](https://developer.android.com/reference/java/util/Spliterator#binding)* , *fail-fast* , and additionally reports `https://developer.android.com/reference/java/util/Spliterator#ORDERED` with an encounter order that is ascending order of the corresponding keys. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Collection.remove`, `removeAll`, `retainAll` and `clear` operations. It does not support the `add` or `addAll` operations.
| Returns || |---|---| | `https://developer.android.com/reference/java/util/Collection` | a collection view of the values contained in this map
|