JavaScript WeakMap set() method

The JavaScript WeakMap set() method is used to add or update an element to WeakMap object with the particular key-value pair. Each value must have a unique key (i.e. object).

Syntax

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

Parameter

key - It represents the key to be added.

value - It represents the value to be added.

Return

The WeakMap object.

JavaScript WeakMap set() method example

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

Example 1

Let's see an example to add elements to WeakMap object.

<script>
var wm = new WeakWeakMap();
var obj1 = {};
var obj2 = {};
var obj3= {};
wm.set(obj1, "jQuery");
wm.set(obj2, "AngularJS");
wm.set(obj3,"Bootstrap");
document.writeln(wm.get(obj1)+"<br>");
document.writeln(wm.get(obj2)+"<br>");
document.writeln(wm.get(obj3));
</script>

Test it Now

Output:

jQuery
AngularJS
Bootstrap

Example 2

Let's see an example to add elements to WeakMap object in chainable form.

<script>
var wm = new WeakMap();
var obj1 = {};
var obj2 = {};
var obj3= {};
wm.set(obj1, "jQuery").set(obj2, "AngularJS").set(obj3,"Bootstrap");
document.writeln(wm.get(obj1)+"<br>");
document.writeln(wm.get(obj2)+"<br>");
document.writeln(wm.get(obj3));
</script>

Test it Now

Output:

jQuery
AngularJS
Bootstrap

Example 3

In this example, we will determine the result when different values are added to the same object.

<script>
var wm = new WeakMap();
var obj1 = {};
var obj2 = {};
wm.set(obj1, "jQuery");
wm.set(obj2, "AngularJS");
wm.set(obj2,"Bootstrap");
document.writeln(wm.get(obj1)+"<br>");
document.writeln(wm.get(obj2)+"<br>");
document.writeln(wm.get(obj2));
</script>

Test it Now

Output: