JavaScript Forum

**luz** · 11-20-2009, 12:43 AM

Hi...i'm still new at this js oo..what i would to do is return value from a one class method to the other..as you all can see below i have 2 simple class which is MyMath and MathResult..the problem is how can i return the value of this.DoMath() which is this.total in MyMath to this.ShowMathResult in MathResult..thanking you all in advance for reviewing my post

Code:

function MyMath(){
    this.StartMath = function(a,b,c){
        this.a = a;
        this.b = b;
        this.c = c;
        this.DoMath();    
    };
    this.DoMath() = function(){
        this.total = this.a +this. b - this.c; 
        return this.total;
    };
    
}
function MathResult(){
    this.ShowMathResult = function(){
         alert(this.total);
    }
}

**tripy** · 11-20-2009, 05:56 AM

First,

Code:

this.DoMath() = function()

is wrong, it should be

Code:

this.DoMath = function()

Second,you need to give a reference from one object to the other, or to give the other object reference to the function that will do the call.
I opted for the second option here, we call this "loose coupling", as it allows us to avoid an hardcoded reference in the second class:

HTML Code:

<html>
<body>
<script type="text/javascript">
function MyMath(){
    this.DoMath = function(){
        this.total = this.a +this. b - this.c; 
        return this.total;
    };
    this.StartMath = function(a,b,c){
        this.a = a;
        this.b = b;
        this.c = c;
        return this.DoMath();    //return the result to the caller, or assign it to a property, but don't let it be lost...
    };
}
function MathResult(){
    this.ShowMathResult = function(mm){
        if(mm===null){
            alert('No MyMath instance given')
        }else{
            alert(mm.StartMath(1,8,5));
        }
    }
}

mm=new MyMath();
mr=new MathResult();

mr.ShowMathResult(mm);
</script>
</body>
</html>