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String.prototype[@@iterator]()

The [@@iterator]() method of String values implements the iterable protocol and allows strings to be consumed by most syntaxes expecting iterables, such as the spread syntax and for...of loops. It returns a string iterator object that yields the Unicode code points of the string value as individual strings.

Try it

Syntax

string[Symbol.iterator]()

Parameters

None.

Return value

A new iterable iterator object that yields the Unicode code points of the string value as individual strings.

Description

Strings are iterated by Unicode code points. This means grapheme clusters will be split, but surrogate pairs will be preserved.

// "Backhand Index Pointing Right: Dark Skin Tone"
[..."👉🏿"]; // ['👉', '🏿']
// splits into the basic "Backhand Index Pointing Right" emoji and
// the "Dark skin tone" emoji

// "Family: Man, Boy"
[..."👨‍👦"]; // [ '👨', '‍', '👦' ]
// splits into the "Man" and "Boy" emoji, joined by a ZWJ

Examples

Iteration using for...of loop

Note that you seldom need to call this method directly. The existence of the @@iterator method makes strings iterable, and iterating syntaxes like the for...of loop automatically call this method to obtain the iterator to loop over.

const str = "A\uD835\uDC68B\uD835\uDC69C\uD835\uDC6A";

for (const v of str) {
  console.log(v);
}
// "A"
// "\uD835\uDC68"
// "B"
// "\uD835\uDC69"
// "C"
// "\uD835\uDC6A"

Manually hand-rolling the iterator

You may still manually call the next() method of the returned iterator object to achieve maximum control over the iteration process.

const str = "A\uD835\uDC68";

const strIter = str[Symbol.iterator]();

console.log(strIter.next().value); // "A"
console.log(strIter.next().value); // "\uD835\uDC68"

Specifications

Specification
ECMAScript Language Specification # sec-string.prototype-@@iterator

Browser compatibility

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	Deno	Node.js
`@@iterator`	38	12	36 27–36 A placeholder property named `@@iterator` is used. 17–27 A placeholder property named `iterator` is used.	25	9	38	36 27–36 A placeholder property named `@@iterator` is used. 17–27 A placeholder property named `iterator` is used.	25	9	3.0	38	1.0	0.12.0