JavaScript WeakSet add() Method

by Online Tutorials Library July 22, 2022

JavaScript Set add() method

The JavaScript Set add() method is used to add a new object to the end of a WeakSet object.

Syntax

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

Parameter

value – It represents the object to be added.

Return

The WeakSet object.

JavaScript Set add() method example

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

Example 1

Let’s see an example to add object to WeakSet object.

  <script>  var ws = new WeakSet();  var obj1={};  var obj2={};  ws.add(obj1);  ws.add(obj2);  //Let’s check whether the WeakSet object contains the added object  document.writeln(ws.has(obj1)+”<br>”);  document.writeln(ws.has(obj2));  </script>  

Test it Now

Output:

true  true

Example 2

In this example, we will see whether we add the objects to WeakSet object without initializing them.

  <script>  var ws = new WeakSet();  try    {  ws.add(obj);  document.writeln(ws.has(obj));        }  catch(error)    {      document.writeln(error);    }  </script>  

Test it Now

Output:

ReferenceError: obj is not defined

Next TopicWeakSet delete() Method