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Message:

class design problem

Posted by Alex on December 02, 2000 at 1:40 PM

> I am having a problem related to the design of classes using java as prog. language.The class heirarchy is like this:
> GroupExpression (Parent class)

> Min Max Avg Sum Count (Child classes)
> These sub classes do the comparison of input parameters
> depending on the class called(e.g Sum class will add the parameters,Count will count the params like that).
> Parent class has Create(arg) and compute(arg1,arg2)methods.Child class will have the compute(arg1,arg2) method.
> Caller will have refernce of Parent class and it will call its create()method to create an instance of reqd sub class.Then it will call the compute() method .

> Now Problem is input parameters can be of type
> int,float,long,double and accordingly the return type.

> Now the code to check for the parameter type and accordingly select the return type or given that if return type is being passed then also the code becomes dirty.
> Tried taking input to compute() method as an object having parameter type and parameter value as its attributes.But this again becomes clumsy.
> Can you suggest me a neat way to overcome the problem.
> Thanks and Regards,
> Manish Dhall

I would overload compute().
I'd have int compute(int a, int b), float compute(float a, float b), long .... etc...

HTH. Alex.