Map.prototype.has()

The has() method returns a boolean indicating whether an element with the specified key exists or not.

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

Specification
ECMAScript Language Specification # sec-map.prototype.has

Browser compatibility

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See also