Assigning a variable value : Reference it instead of copying it

Question

function Picker() {
    this.status = [0, 0, 0];
    this.progress = Picker.status[0];
}

var picker = new Picker();

picker.progress = 2;

Now if I check the information held by progress and status[0] they will be different.

How can I make these a reference instead of copies?

Many thanks

possible duplicate of [What is the most efficient way to clone an object?](http://stackoverflow.com/questions/122102/what-is-the-most-efficient-way-to-clone-an-object) — Curtis, Jul 16 '14 at 11:19
No, I don't this is a duplicate. Why are you trying to get a reference? — Callum Linington, Jul 16 '14 at 11:21
Any reason @Cerbrus? @No1_Melman I am using an array as a misc storage for active data and wanted to add a reference with an easier name to one of them. — Dorjan, Jul 16 '14 at 11:23
Looking at @dystroy's answer, apparently it's actually kinda possible. — Cerbrus, Jul 16 '14 at 11:25

score 1 · Accepted Answer · answered Jul 16 '14 at 11:23

1

There's no simple way, as JavaScript doesn't store primitive values as references, but you can do this :

function Picker() {
    this.status = [0, 0, 0];
    Object.defineProperty(this, 'progress', {
      get : function(){ return this.status[0] },
      set : function(p){ this.status[0] = p },
      enumerable : true
    });
}

var picker = new Picker();
picker.progress = 2;
console.log(picker.status[0]) // logs 2

The most typical solution would probably be to use getters and setters, though, or to change the design.

answered Jul 16 '14 at 11:23

Denys Séguret

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Interesting. I the project is being done with haste (at first) and I haven't coded in a few years thus started without a good structure. I can see this being a solution though! A lot more code than I thought it would be (I expected something like &= :D) – Dorjan Jul 16 '14 at 11:26

Assigning a variable value : Reference it instead of copying it

1 Answers1