# Dictionary Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) # Dictionary ``` abstract class Dictionary ``` |---|----------------------------------------------------------------------------------------------| | [kotlin.Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) || | ↳ | [java.util.Dictionary](https://developer.android.com/reference/kotlin/java/util/Dictionary#) | |-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Known Direct Subclasses [Hashtable](https://developer.android.com/reference/kotlin/java/util/Hashtable) |---------------------------------------------------------------------------------|----------------------------------------------------------------| | [Hashtable](https://developer.android.com/reference/kotlin/java/util/Hashtable) | This class implements a hash table, which maps keys to values. | | |-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Known Indirect Subclasses [AuthProvider](https://developer.android.com/reference/kotlin/java/security/AuthProvider.html#),[Properties](https://developer.android.com/reference/kotlin/java/util/Properties),[Provider](https://developer.android.com/reference/kotlin/java/security/Provider.html#) |-------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------| | [AuthProvider](https://developer.android.com/reference/kotlin/java/security/AuthProvider.html#) | Legacy security code; do not use. | | [Properties](https://developer.android.com/reference/kotlin/java/util/Properties) | The`Properties`class represents a persistent set of properties. | | [Provider](https://developer.android.com/reference/kotlin/java/security/Provider.html#) | This class represents a "provider" for the Java Security API, where a provider implements some or all parts of Java Security. | | The`Dictionary`class is the abstract parent of any class, such as`Hashtable`, which maps keys to values. Every key and every value is an object. In any one`Dictionary`object, every key is associated with at most one value. Given a`Dictionary`and a key, the associated element can be looked up. Any non-`null`object can be used as a key and as a value. As a rule, the`equals`method should be used by implementations of this class to decide if two keys are the same. **NOTE: This class is obsolete. New implementations should implement the Map interface, rather than extending this class.** ## Summary | Public constructors || |----------------------------------------------------------------------------------------------------------------------|---| | [Dictionary](https://developer.android.com/reference/kotlin/java/util/Dictionary#Dictionary())`()` Sole constructor. | | Public methods || |---------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | abstract[Enumeration](https://developer.android.com/reference/kotlin/java/util/Enumeration)\! | [elements](https://developer.android.com/reference/kotlin/java/util/Dictionary#elements())`()` Returns an enumeration of the values in this dictionary. | | abstractV | [get](https://developer.android.com/reference/kotlin/java/util/Dictionary#get(kotlin.Any))`(`key:` `[Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)!`)` Returns the value to which the key is mapped in this dictionary. | | abstract[Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | [isEmpty](https://developer.android.com/reference/kotlin/java/util/Dictionary#isEmpty())`()` Tests if this dictionary maps no keys to value. | | abstract[Enumeration](https://developer.android.com/reference/kotlin/java/util/Enumeration)\! | [keys](https://developer.android.com/reference/kotlin/java/util/Dictionary#keys())`()` Returns an enumeration of the keys in this dictionary. | | abstractV | [put](https://developer.android.com/reference/kotlin/java/util/Dictionary#put(java.util.Dictionary.K,%20java.util.Dictionary.V))`(`key:` `K`, `value:` `V`)` Maps the specified`key`to the specified`value`in this dictionary. | | abstractV | [remove](https://developer.android.com/reference/kotlin/java/util/Dictionary#remove(kotlin.Any))`(`key:` `[Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)!`)` Removes the`key`(and its corresponding`value`) from this dictionary. | | abstract[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [size](https://developer.android.com/reference/kotlin/java/util/Dictionary#size())`()` Returns the number of entries (distinct keys) in this dictionary. | ## Public constructors ### Dictionary Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` Dictionary() ``` Sole constructor. (For invocation by subclass constructors, typically implicit.) ## Public methods ### elements Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun elements(): Enumeration! ``` Returns an enumeration of the values in this dictionary. The general contract for the`elements`method is that an`Enumeration`is returned that will generate all the elements contained in entries in this dictionary. | Return || |-----------------------------------------------------------------------------------------|--------------------------------------------------| | [Enumeration](https://developer.android.com/reference/kotlin/java/util/Enumeration)! | an enumeration of the values in this dictionary. | **See Also** - [java.util.Dictionary#keys()](https://developer.android.com/reference/kotlin/java/util/Dictionary#keys()) - [java.util.Enumeration](https://developer.android.com/reference/kotlin/java/util/Enumeration) ### get Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun get(key: Any!): V ``` Returns the value to which the key is mapped in this dictionary. The general contract for the`isEmpty`method is that if this dictionary contains an entry for the specified key, the associated value is returned; otherwise,`null`is returned. | Parameters || |-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `key` | [Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)!:a key in this dictionary.`null`if the key is not mapped to any value in this dictionary. | | Return || |---|----------------------------------------------------------| | V | the value to which the key is mapped in this dictionary; | | Exceptions || |----------------------------------|----------------------| | `java.lang.NullPointerException` | if the`key`is`null`. | **See Also** - [java.util.Dictionary#put(java.lang.Object, java.lang.Object)](https://developer.android.com/reference/kotlin/java/util/Dictionary#put(java.util.Dictionary.K,%20java.util.Dictionary.V)) ### isEmpty Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun isEmpty(): Boolean ``` Tests if this dictionary maps no keys to value. The general contract for the`isEmpty`method is that the result is true if and only if this dictionary contains no entries. | Return || |------------------------------------------------------------------------------------|-------------------------------------------------------------------| | [Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | `true`if this dictionary maps no keys to values;`false`otherwise. | ### keys Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun keys(): Enumeration! ``` Returns an enumeration of the keys in this dictionary. The general contract for the keys method is that an`Enumeration`object is returned that will generate all the keys for which this dictionary contains entries. | Return || |-----------------------------------------------------------------------------------------|------------------------------------------------| | [Enumeration](https://developer.android.com/reference/kotlin/java/util/Enumeration)! | an enumeration of the keys in this dictionary. | **See Also** - [java.util.Dictionary#elements()](https://developer.android.com/reference/kotlin/java/util/Dictionary#elements()) - [java.util.Enumeration](https://developer.android.com/reference/kotlin/java/util/Enumeration) ### put Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun put(     key: K,     value: V ): V ``` Maps the specified`key`to the specified`value`in this dictionary. Neither the key nor the value can be`null`. If this dictionary already contains an entry for the specified`key`, the value already in this dictionary for that`key`is returned, after modifying the entry to contain the new element. If this dictionary does not already have an entry for the specified`key`, an entry is created for the specified`key`and`value`, and`null`is returned. The`value`can be retrieved by calling the`get`method with a`key`that is equal to the original`key`. | Parameters || |---------|----------------------| | `key` | K:the hashtable key. | | `value` | V:the value. | | Return || |---|------------------------------------------------------------------------------------------------------------------------| | V | the previous value to which the`key`was mapped in this dictionary, or`null`if the key did not have a previous mapping. | | Exceptions || |----------------------------------|-------------------------------| | `java.lang.NullPointerException` | if the`key`or`value`is`null`. | **See Also** - [java.lang.Object#equals(java.lang.Object)](https://developer.android.com/reference/kotlin/java/lang/Object.html#equals(kotlin.Any)) - [java.util.Dictionary#get(java.lang.Object)](https://developer.android.com/reference/kotlin/java/util/Dictionary#get(kotlin.Any)) ### remove Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun remove(key: Any!): V ``` Removes the`key`(and its corresponding`value`) from this dictionary. This method does nothing if the`key`is not in this dictionary. | Parameters || |-------|---------------------------------------------------------------------------------------------------------------| | `key` | [Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)!:the key that needs to be removed. | | Return || |---|-----------------------------------------------------------------------------------------------------------| | V | the value to which the`key`had been mapped in this dictionary, or`null`if the key did not have a mapping. | | Exceptions || |----------------------------------|------------------| | `java.lang.NullPointerException` | if`key`is`null`. | ### size Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun size(): Int ``` Returns the number of entries (distinct keys) in this dictionary. | Return || |----------------------------------------------------------------------------|----------------------------------------| | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | the number of keys in this dictionary. |