javascript / latest / global_objects / map / @@iterator.html /

Map.prototype[@@iterator]()

The initial value of the @@iterator property is the same function object as the initial value of the entries method.

Try it

Syntax

myMap[Symbol.iterator]

Return value

The map iterator function, which is the entries() function by default.

Examples

Using [@@iterator]()

const myMap = new Map()
myMap.set('0', 'foo')
myMap.set(1, 'bar')
myMap.set({}, 'baz')

const mapIter = myMap[Symbol.iterator]()

console.log(mapIter.next().value) // ["0", "foo"]
console.log(mapIter.next().value) // [1, "bar"]
console.log(mapIter.next().value) // [Object, "baz"]

Using [@@iterator]() with for..of

const myMap = new Map()
myMap.set('0', 'foo')
myMap.set(1, 'bar')
myMap.set({}, 'baz')

for (const entry of myMap) {
  console.log(entry)
}
// ["0", "foo"]
// [1, "bar"]
// [{}, "baz"]

for (const [key, value] of myMap) {
  console.log(`${key}: ${value}`)
}
// 0: foo
// 1: bar
// [Object]: baz

Specifications

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet Deno Node.js
@@iterator
43
12
36
27-36
A placeholder property named @@iterator is used.
17-27
A placeholder property named iterator is used.
No
30
10
43
43
36
27-36
A placeholder property named @@iterator is used.
17-27
A placeholder property named iterator is used.
30
10
4.0
1.0
0.12.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/@@iterator