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.assert(Object.isExtensible(jj) === false);

// no error if arg is not object
console.assert(Object.preventExtensions(3) === 3);