The has() method of Map instances returns a boolean indicating whether an element with the specified key exists in this map or not.
Map.prototype.has()
Try it
Syntax
js
has(key)
Parameters
-
key -
The key of the element to test for presence in the
Mapobject.
Return value
true if an element with the specified key exists in the Map object; otherwise false.
Examples
Using has()
js
const myMap = new Map();
myMap.set("bar", "foo");
console.log(myMap.has("bar")); // true
console.log(myMap.has("baz")); // false
Specifications
Browser compatibility
| Desktop | Mobile | Server | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | Deno | Node.js | ||
has |
38 | 12 | 13 | 25 | 8 | 38 | 14 | 25 | 8 | 3.0 | 38 | 1.0 | 0.12.0 | |
See also
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/has