Array.prototype.entries()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since May 2018.

The entries() method of Array instances returns a new array iterator object that contains the key/value pairs for each index in the array.

Try it

const array1 = ["a", "b", "c"];

const iterator1 = array1.entries();

console.log(iterator1.next().value);
// Expected output: Array [0, "a"]

console.log(iterator1.next().value);
// Expected output: Array [1, "b"]

Syntax

js
entries()

Parameters

None.

Return value

Description

When used on sparse arrays, the entries() method iterates empty slots as if they have the value undefined.

The entries() method is generic. It only expects the this value to have a length property and integer-keyed properties.

Examples

Iterating with index and element

js
const a = ["a", "b", "c"];

for (const [index, element] of a.entries()) {
  console.log(index, element);
}

// 0 'a'
// 1 'b'
// 2 'c'

Using a for...of loop

js
const array = ["a", "b", "c"];
const arrayEntries = array.entries();

for (const element of arrayEntries) {
  console.log(element);
}

// [0, 'a']
// [1, 'b']
// [2, 'c']

Iterating sparse arrays

entries() will visit empty slots as if they are undefined.

js
for (const element of [, "a"].entries()) {
  console.log(element);
}
// [0, undefined]
// [1, 'a']

Calling entries() on non-array objects

The entries() method reads the length property of this and then accesses each property whose key is a nonnegative integer less than length.

js
const arrayLike = {
  length: 3,
  0: "a",
  1: "b",
  2: "c",
  3: "d", // ignored by entries() since length is 3
};
for (const entry of Array.prototype.entries.call(arrayLike)) {
  console.log(entry);
}
// [ 0, 'a' ]
// [ 1, 'b' ]
// [ 2, 'c' ]

Specifications

Specification
ECMAScript® 2025 Language Specification
# sec-array.prototype.entries

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
entries

Legend

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Full support
Full support

See also