StringJoiner
class StringJoiner
kotlin.Any | |
↳ | java.util.StringJoiner |
StringJoiner
is used to construct a sequence of characters separated by a delimiter and optionally starting with a supplied prefix and ending with a supplied suffix.
Prior to adding something to the StringJoiner
, its sj.toString()
method will, by default, return prefix + suffix
. However, if the setEmptyValue
method is called, the emptyValue
supplied will be returned instead. This can be used, for example, when creating a string using set notation to indicate an empty set, i.e. "{}"
, where the prefix
is "{"
, the suffix
is "}"
and nothing has been added to the StringJoiner
.
Summary
Public constructors | |
---|---|
StringJoiner(delimiter: CharSequence!) Constructs a |
|
StringJoiner(delimiter: CharSequence!, prefix: CharSequence!, suffix: CharSequence!) Constructs a |
Public methods | |
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StringJoiner! |
add(newElement: CharSequence!) Adds a copy of the given |
Int |
length() Returns the length of the |
StringJoiner! |
merge(other: StringJoiner!) Adds the contents of the given |
StringJoiner! |
setEmptyValue(emptyValue: CharSequence!) Sets the sequence of characters to be used when determining the string representation of this |
String |
toString() Returns the current value, consisting of the |
Public constructors
StringJoiner
StringJoiner(delimiter: CharSequence!)
Constructs a StringJoiner
with no characters in it, with no prefix
or suffix
, and a copy of the supplied delimiter
. If no characters are added to the StringJoiner
and methods accessing the value of it are invoked, it will not return a prefix
or suffix
(or properties thereof) in the result, unless setEmptyValue
has first been called.
Parameters | |
---|---|
delimiter |
CharSequence!: the sequence of characters to be used between each element added to the StringJoiner value |
Exceptions | |
---|---|
java.lang.NullPointerException |
if delimiter is null |
StringJoiner
StringJoiner(
delimiter: CharSequence!,
prefix: CharSequence!,
suffix: CharSequence!)
Constructs a StringJoiner
with no characters in it using copies of the supplied prefix
, delimiter
and suffix
. If no characters are added to the StringJoiner
and methods accessing the string value of it are invoked, it will return the prefix + suffix
(or properties thereof) in the result, unless setEmptyValue
has first been called.
Parameters | |
---|---|
delimiter |
CharSequence!: the sequence of characters to be used between each element added to the StringJoiner |
prefix |
CharSequence!: the sequence of characters to be used at the beginning |
suffix |
CharSequence!: the sequence of characters to be used at the end |
Exceptions | |
---|---|
java.lang.NullPointerException |
if prefix , delimiter , or suffix is null |
Public methods
add
fun add(newElement: CharSequence!): StringJoiner!
Adds a copy of the given CharSequence
value as the next element of the StringJoiner
value. If newElement
is null
, then "null"
is added.
Parameters | |
---|---|
newElement |
CharSequence!: The element to add |
Return | |
---|---|
StringJoiner! |
a reference to this StringJoiner |
length
fun length(): Int
Returns the length of the String
representation of this StringJoiner
. Note that if no add methods have been called, then the length of the String
representation (either prefix + suffix
or emptyValue
) will be returned. The value should be equivalent to toString().length()
.
Return | |
---|---|
Int |
the length of the current value of StringJoiner |
merge
fun merge(other: StringJoiner!): StringJoiner!
Adds the contents of the given StringJoiner
without prefix and suffix as the next element if it is non-empty. If the given StringJoiner
is empty, the call has no effect.
A StringJoiner
is empty if add()
has never been called, and if merge()
has never been called with a non-empty StringJoiner
argument.
If the other StringJoiner
is using a different delimiter, then elements from the other StringJoiner
are concatenated with that delimiter and the result is appended to this StringJoiner
as a single element.
Parameters | |
---|---|
other |
StringJoiner!: The StringJoiner whose contents should be merged into this one |
Return | |
---|---|
StringJoiner! |
This StringJoiner |
Exceptions | |
---|---|
java.lang.NullPointerException |
if the other StringJoiner is null |
setEmptyValue
fun setEmptyValue(emptyValue: CharSequence!): StringJoiner!
Sets the sequence of characters to be used when determining the string representation of this StringJoiner
and no elements have been added yet, that is, when it is empty. A copy of the emptyValue
parameter is made for this purpose. Note that once an add method has been called, the StringJoiner
is no longer considered empty, even if the element(s) added correspond to the empty String
.
Parameters | |
---|---|
emptyValue |
CharSequence!: the characters to return as the value of an empty StringJoiner |
Return | |
---|---|
StringJoiner! |
this StringJoiner itself so the calls may be chained |
Exceptions | |
---|---|
java.lang.NullPointerException |
when the emptyValue parameter is null |
toString
fun toString(): String
Returns the current value, consisting of the prefix
, the values added so far separated by the delimiter
, and the suffix
, unless no elements have been added in which case, the prefix + suffix
or the emptyValue
characters are returned.
Return | |
---|---|
String |
the string representation of this StringJoiner |