isExtensible()

The static method Reflect.isExtensible serves the purpose of determining whether an object can be extended. This method functions similarly to Object.isExtensible, though with some distinctions.

Syntax:

Reflect.isExtensible(obj)

Parameters:

Obj: This refers to the object in question that is being evaluated for its extensibility.

Return value:

This function yields a Boolean value that signifies whether the target can be extended or not.

Exceptions:

A TypeError, if the target is not an Object.

Browser Support:

Example 1

const object = {};
console.log(Reflect.isExtensible(object));
Reflect.preventExtensions(object);
console.log(Reflect.isExtensible(object));

Output:

true
 false

Example 2

const object2 = Object.seal({});

console.log(Reflect.isExtensible(object2));

const object3 = Object.seal({});
console.log(Reflect.isExtensible(object3));

Output:

false
 false

Example 3

const object = {};
const object1 = {};
console.log(Reflect.isExtensible(object1));
Reflect.preventExtensions(object);
console.log(Reflect.isExtensible(object));

Output:

true
false