Question

How do you check whether an object can be extendable or not?

Answer 1

The Object.isExtensible() method is used to determine if an object is extendable or not. i.e, Whether it can have new properties added to it or not.

const newObject = {};
console.log(Object.isExtensible(newObject)); //true

Note: By default, all the objects are extendable. i.e, The new properties can be added or modified.