immutable objects in node should be declared let, var or const? is there some difference?

Question

The following code build an immutable object:

Object.freeze({ "foo" : "bar" })

Is there some difference in creation using

• var
• let
• const

?

Answer 1

The difference is that

const foo = Object.freeze({ "foo" : "bar" });

cannot be later reassigned with

foo = 'baz';

While var and let can.

Immutability is orthogonal to reassignment. There may be a need for a variable that stores immutable object to be reassigned, there may be a need to store mutable object in const.