Do you know what will be the output of this code? const obj = Object.freeze({ a: 1, inner: { b: 1 } }); obj.a = 2; obj.inner.b = 2; console.log(obj.a, obj.inner.b);

Is Object.freeze deep or shallow?

Do you know what will be the output of this code?

JavaScript

const obj = Object.freeze({ a: 1, inner: { b: 1 } });
obj.a = 2;
obj.inner.b = 2;
console.log(obj.a, obj.inner.b);

Show answer and explanation

The answer is 1 2.

Object.freeze is shallow. The change to obj.a is ignored (in strict mode it throws), but inner is a separate object that isn’t frozen.