Object.freeze() vs const

Question

Object.freeze() seems like a transitional convenience method to move towards using const in ES6.

Are there cases where both take their place in the cod

Answer 1

In ES5 Object.freeze doesn't work on primitives, which would probably be more commonly declared using const than objects. You can freeze primitives in ES6, but then you also have support for const.

On the other hand const used to declare objects doesn't "freeze" them, you just can't redeclare the whole object, but you can modify its keys freely. On the other hand you can redeclare frozen objects.

Object.freeze is also shallow, so you'd need to recursively apply it on nested objects to protect them.

var ob1 = {
   foo : 1,
    bar : {
        value : 2   
    }
};
Object.freeze( ob1 );

const ob2 = {
   foo : 1,
    bar : {
        value : 2   
    }
}

ob1.foo = 4;  // (frozen) ob1.foo not modified
ob2.foo = 4;  // (const) ob2.foo modified

ob1.bar.value = 4;  // (frozen) modified, because ob1.bar is nested
ob2.bar.value = 4;  // (const) modified

ob1.bar = 4;  // (frozen) not modified, bar is a key of obj1
ob2.bar = 4;  // (const) modified

ob1 = {};  // (frozen) ob1 redeclared
ob2 = {}; // (const) ob2 not redeclared