# Iterator — Description

> The following are all built-in JavaScript iterators The _Array Iterator_ returned by {{jsxref("Array.prototype.values()")}}, {{jsxref("Array.prototype.keys()")}}, {{jsxref("Array.prototype.entries()")}}, Array.prototype[Symbol.iterator](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Symbo

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- Updated: `2026-08-16T09:32:14.499781+00:00`
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## Knowledge

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The following are all built-in JavaScript iterators

The _Array Iterator_ returned by {{jsxref("Array.prototype.values()")}}, {{jsxref("Array.prototype.keys()")}}, {{jsxref("Array.prototype.entries()")}}, Array.prototype[Symbol.iterator](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Symbol.iterator), {{jsxref("TypedArray.prototype.values()")}}, {{jsxref("TypedArray.prototype.keys()")}}, {{jsxref("TypedArray.prototype.entries()")}}, TypedArray.prototype[Symbol.iterator](/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/Symbol.iterator), and arguments[Symbol.iterator](/en-US/docs/Web/JavaScript/Reference/Functions/arguments/Symbol.iterator). The _String Iterator_ returned by String.prototype[Symbol.iterator](/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/Symbol.iterator). The _Map Iterator_ returned by {{jsxref("Map.prototype.values()")}}, {{jsxref("Map.prototype.keys()")}}, {{jsxref("Map.prototype.entries()")}}, and Map.prototype[Symbol.iterator](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/Symbol.iterator). The _Set Iterator_ returned by {{jsxref("Set.prototype.values()")}}, {{jsxref("Set.prototype.keys()")}}, {{jsxref("Set.prototype.entries()")}}, and Set.prototype[Symbol.iterator](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/Symbol.iterator). The _RegExp String Iterator_ returned by RegExp.prototype[Symbol.matchAll](/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/Symbol.matchAll) and {{jsxref("String.prototype.matchAll()")}}. The {{jsxref("Generator")}} object returned by generator functions. The _Segments Iterator_ returned by the [Symbol.iterator](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Segmenter/segment/Segments/Symbol.iterator) method of the Segments object returned by Intl.Segmenter.prototype.segment(). The _Iterator Helper_ returned by iterator helper methods such as {{jsxref("Iterator.prototype.filter()")}} and {{jsxref("Iterator.prototype.map()")}}.

Web APIs may return iterators too. Some reuse core JavaScript iterators while others define their own iterators. For example …

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