JavaScript | weakSet.has() with Examples

The weakSet.has() is an inbuilt function in JavaScript which is used to return a boolean value indicating whether an object is present in a weakSet or not. The WeakSet object lets you store weakly held objects in a collection.
Syntax:

weakSet.has(A);

Parameters: It accepts the parameter “A” which is a value going to be checked whether it is present in the weakSet object or not.
Return Values: It returns boolean value true if the element is present otherwise it returns false.

JavaScript code to show the working of this function:

Code #1:

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<script>
  
   // Constructing a weakSet() object
   const A = new WeakSet();
  
   // Constructing new objects
   const object1 = {};
  
   // Adding the new object to the weakSet
   A.add(object1);
  
   // Checking whether the new object is present
   // in the weakSet or not
   document.write(A.has(object1) +"<br>");
  
</script>

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Output:


        
          
          
          
        

            

true


Here output is true because the object “object1” is present in the WeakSet() object.

Code #2:











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<script> 


  


   // Constructing a weakSet() object 


   const A = new WeakSet(); 


  


   // Constructing new objects 


   const object1 = {}; 


  


   // Checking whether the new object is present 


   // in the weakSet or not 


   document.write(A.has(object1) +"<br>"); 


  


</script> 



















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Output:


false


Here output is false because the object “object1” is not present in the WeakSet() object.



          
          
          

          

    

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