JavaScript Map has() method

The JavaScript map has() method indicates whether the Map object contains the specified key. It returns true if the specified key is present, otherwise false.

Syntax

The has() method is represented by the following syntax:

Parameter

key - It represents the key to be searched.

Return

A Boolean value.

JavaScript Map has() method example

Here, we will understand has() method through various examples.

Example 1

Let's see an example to determine whether the map object contains the specified key.

<script>
var map=new Map();
map.set(1,"jQuery");
map.set(2,"AngularJS");
map.set(3,"Bootstrap");
document.writeln(map.has(2)); 
</script>

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Output:

true

Example 2

Let's see one more example to determine whether the map object contains the specified key.

<script>
var map=new Map();
map.set(1,"jQuery");
map.set(2,"AngularJS");
map.set(3,"Bootstrap");
document.writeln(map.has(5)); 
</script>

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Output:

false

Example 3

Let's see the result when has() method is used without specifying key.

<script>
var map=new Map();
map.set(1,"jQuery");
map.set(2,"AngularJS");
map.set(3,"Bootstrap");
document.writeln(map.has()+"<br>");
document.writeln(map.has("jQuery")); 
</script>

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Output: