Javascript manual

Objects and functions

Suppose, you have an object declared like this var person = { height : 6, weight : 200, change : function () { this.height = 5; } }

When you first make this object like this:

var joshua = new person();

Then Joshua starts with a height of 6. But when you call his change method:

joshua.change();

Joshua’s height is now 5. So,

joshua.height will evaluate to 5.