Map.prototype.has()

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

Try it

Syntax

js

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()

js

const myMap = new Map();
myMap.set("bar", "foo");

console.log(myMap.has("bar")); // true
console.log(myMap.has("baz")); // false

Specifications

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

Browser compatibility

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See also