JavaScript new.target meta Property

The new.target pseudo-property let us detect whether a function or constructor is called with the help of new operator or not.

Syntax:

new.target

The following example demonstrates the meta property.

Example 1: In this example, the function is called without the new operator.

HTML

<!DOCTYPE HTML> 
<html> 
  
<body style="text-align:center;"> 
    <h1 style="color:green;"> 
        GeeksForGeeks 
    </h1> 
  
    <p> 
        JavaScript | new.target metaKey property 
    </p> 
      
    <button onclick="Geeks();"> 
        click here 
    </button> 
      
    <p id="GFG_DOWN"></p> 
  
    <script> 
        var el_down = document 
                .getElementById("GFG_DOWN"); 
  
        function Fun() { 
            if (!new.target) { 
                throw  
    'Fun() is called without new operator'; 
            } 
        } 
        function Geeks(event) { 
            try { 
                Fun(); 
            } catch (e) { 
                el_down.innerHTML = e; 
            } 
        }  
    </script> 
</body> 
  
</html> 

Output:

Example 2: In this example, the function is called with the new operator.

HTML

<!DOCTYPE HTML> 
<html> 
  
<body style="text-align:center;"> 
    <h1 style="color:green;"> 
        GeeksForGeeks 
    </h1> 
    <p> 
        JavaScript | new.target metaKey property 
    </p> 
  
    <button onclick="Geeks();"> 
        click here 
    </button> 
      
    <p id="GFG_DOWN"></p> 
  
    <script> 
        var el_down = document 
                .getElementById("GFG_DOWN"); 
        class Person { 
            constructor(name) { 
                this.name = name; 
                if (!new.target) { 
throw 'Function is called without new operator'; 
                } 
                else { 
throw 'Function is called with new operator'; 
                } 
            } 
        } 
        function Geeks(event) { 
            try { 
                var p = new Person('GFG'); 
            } catch (e) { 
                el_down.innerHTML = e; 
            } 
        }  
    </script> 
</body> 
  
</html> 

Output:

My Personal Notes

HTML

HTML

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