If you know C/C++, the code 'const info = []' makes 'info' a constant pointer to a list not a pointer to a constant list.

If you want to stop a variable from being changed, use Object.freeze() - https://developer.mozilla.org/en/docs/Web/JavaScript/Referen...

This also means that objects defined with const can be mutated:

const x = { y: 2 }; x.y = 3;

Doesn't error. However with types that are immutable, like numbers and strings, const really is a constant: const HELLO = "hi" will never change.

const number = 1337;

number = 10; // fails

But objects/arrays are not immutable in js, so you can do this:

const person = { name: 'Dude' };

person.name = 'Dudette';

Which is perfectly valid. If you want full immutability, i recommend you check out https://facebook.github.io/immutable-js/, been running it in production, a real pleasure to work with.

Only in development mode, by freezing the objects.

    function deepFreeze(obj) {
      const out = Object.freeze(obj);
      Object.keys(out).forEach(key => {
        if (typeof out[key] === 'object') {
          out[key] = Object.freeze(out[key]);
        }
      });
      return out;
    }

(recursive)

Rust has similar semantics: https://is.gd/hsRjPh versus https://is.gd/ROgzXl

IIRC you can also declare const objects in C++, but constness is more complex and overridden there.