How to create objects inside objects?

[joefraga]

Hi

I have a javascript "class" that generates some html and handle some events and so. I want to have a "sub class" (an instance of an object) that is a child of the first one. The problem is that I can't access the parent object from the seccond one. Is something like this:

function B()
{
 
   this.send_alert = function() { alert(this.parent); }
}
function A()
{
   var _a = 5;
   var _b = new B();
   _b.send_alert();
}

That doesn't work. Any suggestions please?
Thanks

[gits]

Hi,

it works the way you did (i added an instance of A) ... but be aware with the this-keyword. when using objects this refers to the actual object-context so your alert will show 'B-parent' ... ok?

<script>
 
function B() {
    this.parent = 'B-Parent';
    this.send_alert = function() { alert(this.parent); }
}
 
function A() {
    this.parent = 'A-Parent';
 
    var _a = 5;
    var _b = new B();
 
    _b.send_alert();
}
 
var a = new A;
 
</script>

to get the 'A-Parent' you have to use the call-method that calls the method within the execution-context that you pass as a parameter:

<script>
 
function B() {
    this.parent = 'B-Parent';
    this.send_alert = function() { alert(this.parent); }
}
 
function A() {
    this.parent = 'A-Parent';
 
    var _a = 5;
    var _b = new B();
 
    _b.send_alert.call(this);
}
 
var a = new A;
 
</script>
 

kind regards