Whats the difference between using 'this' and the object name for reference inside the object?

Question

If I have the following code:

var obj = {

    x: 34,

    init: function() {
        alert(this.x);
        alert(obj.x)
    }

};

Both al

Answer 1

this inside the function is not necessarily the same as obj. It depends on how the function is called.

• if called using obj.init(), obj will be the same as this.
• if called using an event handler, or something like setTimeout setTimeout(obj.init, 500), this will be the global object (window in browsers, unless you're using strict mode)

Good MDN reference on all of this