# class String

#### no package

Available on all platforms

The basic String class.

A Haxe String is immutable, it is not possible to modify individual characters. No method of this class changes the state of `this` String.

Strings can be constructed using the String literal syntax `"string value"`.

String can be concatenated by using the `+` operator. If an operand is not a String, it is passed through `Std.string()` first.

See:

https://haxe.org/manual/std-String.html

### Constructor

###

`new (string:String)`

Creates a copy from a given String.

### Variables

###

`read onlylength:Int`

The number of characters in `this` String.

### Methods

###

`charAt (index:Int):String`

Returns the character at position `index` of `this` String.

If `index` is negative or exceeds `this.length`, the empty String `""` is returned.

###

`charCodeAt (index:Int):Null<Int>`

Returns the character code at position `index` of `this` String.

If `index` is negative or exceeds `this.length`, `null` is returned.

To obtain the character code of a single character, `"x".code` can be used instead to inline the character code at compile time. Note that this only works on String literals of length 1.

###

`indexOf (str:String, ?startIndex:Int):Int`

Returns the position of the leftmost occurrence of `str` within `this` String.

If `startIndex` is given, the search is performed within the substring of `this` String starting from `startIndex`. Otherwise the search is performed within `this` String. In either case, the returned position is relative to the beginning of `this` String.

If `str` cannot be found, -1 is returned.

###

`lastIndexOf (str:String, ?startIndex:Int):Int`

Returns the position of the rightmost occurrence of `str` within `this` String.

If `startIndex` is given, the search is performed within the substring of `this` String from 0 to `startIndex`. Otherwise the search is performed within `this` String. In either case, the returned position is relative to the beginning of `this` String.

If `str` cannot be found, -1 is returned.

###

`split (delimiter:String):Array<String>`

Splits `this` String at each occurrence of `delimiter`.

If `this` String is the empty String `""`, the result is not consistent across targets and may either be `[]` (on Js, Cpp) or `[""]`.

If `delimiter` is the empty String `""`, `this` String is split into an Array of `this.length` elements, where the elements correspond to the characters of `this` String.

If `delimiter` is not found within `this` String, the result is an Array with one element, which equals `this` String.

If `delimiter` is null, the result is unspecified.

Otherwise, `this` String is split into parts at each occurrence of `delimiter`. If `this` String starts (or ends) with `delimiter`, the result `Array` contains a leading (or trailing) empty String `""` element. Two subsequent delimiters also result in an empty String `""` element.

###

`substr (pos:Int, ?len:Int):String`

Returns `len` characters of `this` String, starting at position `pos`.

If `len` is omitted, all characters from position `pos` to the end of `this` String are included.

If `pos` is negative, its value is calculated from the end of `this` String by `this.length + pos`. If this yields a negative value, 0 is used instead.

If the calculated position + `len` exceeds `this.length`, the characters from that position to the end of `this` String are returned.

If `len` is negative, the result is unspecified.

###

`substring (startIndex:Int, ?endIndex:Int):String`

Returns the part of `this` String from `startIndex` to but not including `endIndex`.

If `startIndex` or `endIndex` are negative, 0 is used instead.

If `startIndex` exceeds `endIndex`, they are swapped.

If the (possibly swapped) `endIndex` is omitted or exceeds `this.length`, `this.length` is used instead.

If the (possibly swapped) `startIndex` exceeds `this.length`, the empty String `""` is returned.

###

`toLowerCase ():String`

Returns a String where all characters of `this` String are lower case.

Affects the characters `A-Z`. Other characters remain unchanged.

###

`toString ():String`

Returns the String itself.

###

`toUpperCase ():String`

Returns a String where all characters of `this` String are upper case.

Affects the characters `a-z`. Other characters remain unchanged.

### Static methods

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`staticfromCharCode (code:Int):String`

Returns the String corresponding to the character code `code`.

If `code` is negative or has another invalid value, the result is unspecified.