JavaScript new.target meta Property
Last Updated :
14 Jul, 2020
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:
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