Javascript Execution Context Of Function Argument

function Apple(){ this.name='apple'; } function Orange(){ this.name='orange'; this.apple = new Apple(); this.apple.onCalled=function(){ alert(this.name);

Solution 1:

Use a closure.

functionOrange(){
    this.name="orange";

    this.apple = newApple();
    var that = this;
    this.apple.onCalled=function() {
        alert(that.name);
    }
}

Have a read how keyword this works in JS, it's a bit tricky but easy to grasp.

Solution 2:

You could write:

Orange.prototype.onCalled=function(){
    this.apple.onCalled.call(this);
}

It's hard to give a general answer. The thing to understand is that this is bound upon any function call. That can be explicitly controlled with the call or apply functions, or by the . operator when accessing a function as a property of an object.

The answer Kos gives about using a closure may also be relevant; it depends on the effect you want.

Solution 3:

Orange.prototype.onCalled=function(){
    this.apple.onCalled.call(this);
}

Example: http://jsfiddle.net/XrtZe/

Have a look at: Scope in JavaScript