JS: Object.preventExtensions

Object.preventExtensions(obj)

• Make obj not extensible.
• Return obj.
• No error if obj is not a object type.

💡 TIP: use Reflect.preventExtensions instead.

// make an object not extensible
const jj = {};
Object.preventExtensions(jj);
console.log(Object.isExtensible(jj) === false);