String.prototype[Symbol.iterator]()

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

{{InteractiveExample("JavaScript Demo: String.prototypeSymbol.iterator")}}

```js interactive-example const str = "The quick red fox jumped over the lazy dog's back.";

const iterator = strSymbol.iterator; let theChar = iterator.next();

while (!theChar.done && theChar.value !== " ") { console.log(theChar.value); theChar = iterator.next(); // Expected output: "T" // "h" // "e" }

## Syntax

```js-nolint
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 [Symbol.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#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• Polyfill of String.prototype[Symbol.iterator] in core-js
• Numbers and strings guide
• {{jsxref("Symbol.iterator")}}
• Iteration protocols