Question

I have a question about JavaScript. I’m currently using code similar to the code below:

function Game() {

}

I want to nest objects, so I can access them like so:

var a = new Game();
a.nested_object.method();
a.nested_object.property;

How would I go about doing this? Would I use a function or {}? Or does it even matter? The code below is an example code of what I am referring to.

function Game() {

this.id;

var stats = {};

}

Like I’ve stated above, can I access stats like so:

var a = new Game();
a.stats

Answer 1

Yes, that’s exactly the way to go.

Notice that the this keyword in your method() will hold the nested_object, not your Game instance. You can get a reference to that only by using a variable pointing to:

function Game() {
    var that = this; // the Game instance
    this.id = …;
    this.nested_object = {
        property: "nested!",
        method: function() {
            this.property; // nested! (=== that.nested_object.property)
            that.id // the game property
        }
    };
}
var game = new Game;
game.nested_object.method();

Because of that nested objects on the prototype (where you don’t have a variable containing the instance) will seldom make much sense – see Crockford's Prototypal inheritance – Issues with nested objects.