JavaScript weakSet.add() Method

Last Updated : 17 Sep, 2020

Below is the example of weakSet.add() method.

Example:

<script>   
    function gfg() {   
    const weakset = new WeakSet();  
  
    const object1 = {};  
    weakset.add(object1);  
    document.write(weakset.has(object1));   
    }   
    gfg();   
</script> 

Output:
```
true
```

The weakSet.add() is an inbuilt function in JavaScript which is used to add an object at the end of the a object WeakSet. The WeakSet object lets you store weakly held objects in a collection.

Syntax:

weakSet.add(A);

Parameters: It accepts the parameter “A” which is a value going to be added to the weakset object.

Return Values: It returns the weakset object.

Example:

Input: weakset.add(object1); 
Output: true

JavaScript code to show the working of the this function:
Code #1:

<script> 
  
    // Constructing a weakset object 
    const weakset = new WeakSet(); 
  
    // Constructing a new object object1 
    const object1 = {}; 
    const object2 = {}; 
    const object3 = {}; 
    const object4 = {}; 
  
    // Adding the object1 at the end of the weakset object. 
    weakset.add(object1); 
    weakset.add(object2); 
    weakset.add(object3); 
    weakset.add(object4); 
  
    // Printing either object has been added or not 
    document.write(weakset.has(object1) +"<br>"); 
    document.write(weakset.has(object2) +"<br>"); 
    document.write(weakset.has(object3) +"<br>"); 
    document.write(weakset.has(object4)); 
      
</script> 

Output:

true
true
true
true

Code #2:

<script> 
  
    // Constructing a weakset object 
    const weakset = new WeakSet(); 
  
    // Constructing a new object object1 
    const object1 = {}; 
    const object2 = {}; 
    const object3 = {}; 
    const object4 = {}; 
  
    // Printing either object has been added or not 
    document.write(weakset.has(object1) +"<br>"); 
    document.write(weakset.has(object2) +"<br>"); 
    document.write(weakset.has(object3) +"<br>"); 
    document.write(weakset.has(object4)); 
      
</script> 