The has()
method returns a boolean indicating whether an element with the specified key exists or not.
Map.prototype.has()
Try it
Syntax
has(key)
Parameters
-
key
-
The key of the element to test for presence in the
Map
object.
Return value
true
if an element with the specified key exists in the Map
object; otherwise false
.
Examples
Using has()
let myMap = new Map() myMap.set('bar', "foo") myMap.has('bar') // returns true myMap.has('baz') // returns false
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 | |
has |
38
|
12
|
13
|
11
|
25
|
8
|
38
|
38
|
14
|
25
|
8
|
3.0
|
1.0
|
0.12.0
0.10.0
|
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/has