Use math operators on generic variables in a generic Java class

generics, java, math

Solution

What you will need to do is use the double value of the `Number`. However, this means that you cannot return the `Number` type.

public double getArea()
{
    return  3.14 * 
            (circle.getRadius().doubleValue()) * 
            (circle.getRadius().doubleValue());      
}

Problem

I'm trying to write some code that will allow me to perform basic math operations on a "T extends Number" object instance. It needs to be able to handle any number type that is a subclass of `Number`. I know some of the types under `Number` have `.add()` methods built in, and some even have `.multiply()` methods. I need to be able to multiply two generic variables of any possible type. I've searched and searched and haven't been able to come up with a clear answer of any kind. ``` public class Circle<T extends Number> { private T center; private T radius; private T area; // constructor and other various mutator methods here.... /** The getArea method returns a Circle object's area. @return The product of Pi time Radius squared. */ public Number getArea() { return 3.14 * (circle.getRadius()) * (circle.getRadius()); } ``` Any help would be much appreciated. Generics are the most difficult thing I've encountered in learning Java. I don't mind doing the leg work because I learn better that way, so even a strong point in the right direction would be very helpful.

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