Reflect.isExtensible() JavaScript

The JavaScript Reflect.isExtensible() method determines if an object is extensible or not. It is similar to Object.isExtensible().

Syntax:

Reflect.isExtensible(obj)

Parameters:

target: It represents the object which to check if it is extensible.

Return: It returns true if the object is extensible otherwise returns false.

Note: It throws TypeError, if the target is not an Object.

Reflect.isExtensible() VS Object.isExtensible()

Reflect.isExtensible(31);
// It throws TypeError: 31 is not an object

Object.isExtensible(31);
// It returns false

Example 1:

<!DOCTYPE html>
<html>
<body>
<script>
const obj = {prop:100};
document.write(Reflect.isExtensible(obj));
</script>
</body>
</html>

Example 2:

<!DOCTYPE html>
<html>
<body>
<script>
const object1 = {};
document.write(Reflect.isExtensible(object1));
document.write("</br>");
Reflect.preventExtensions(object1);
document.write(Reflect.isExtensible(object1));
document.write("</br>");
const object2 = Object.seal({});
document.write(Reflect.isExtensible(object2));
</script>
</body>
</html>