The has()
method returns a boolean indicating whether an element with the specified key exists or not.
The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.
Syntax
myMap.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
Specification |
---|
ECMAScript (ECMA-262) The definition of 'Map.prototype.has' in that specification. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | Server | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
has | Chrome Full support 38 | Edge Full support 12 | Firefox Full support 13 | IE Full support 11 | Opera Full support 25 | Safari Full support 8 | WebView Android Full support 38 | Chrome Android Full support 38 | Firefox Android Full support 14 | Opera Android Full support 25 | Safari iOS Full support 8 | Samsung Internet Android Full support 3.0 | nodejs
Full support
0.12
|
Legend
- Full support
- Full support
- User must explicitly enable this feature.
- User must explicitly enable this feature.