Thread: get and set ???

Your code is all wrong. A class is an object. The object itself does not ask for the information. That's the job of the function that uses the object.
Since this is a circle, the circle must have a radius. But the class itself is the circle. That is the essence of objects. Thus, you can manipulate the circle by setting its radius, and likewise, you cal also get or retrieve the radius later.
(A circle can't speak, so it can't ask for information.)

I already told you. It doesn't make any sense for get/set because you got the essence of an class all wrong.

Yes, set takes an argument that specifies the radius and the function the uses the object asks the user and then calls the member function.

You have the class declaration somewhere and this class has a float member for radius? The get and set function should allow the outside code to retrieve and set the value of this member variable.

I think you should be able to see what getters and setters do in any beginner's tutorial on classes.

Could you post the contents of Circle.h?

How about you go around looking on a class tutorial?

No, the circle constructor is not where you put "ask user questions" code, in general.

I would put the question in main() or some other "not part of the class" function.

And strictly speaking, if you use C++, you should formulate your question using "cout" and "cin".

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Mats

Originally Posted by m37h0d

what you'd want to do is something like this:

Code:

class circle
{
        private:
        float fArea;
        float fRadius;
        float fDiameter;
        float fCircumference;
        public:
        __property void set_radius(float r)
        {
                fRadius = r;
                fArea = PI*r*r;
                fDiameter = 2*r;
                fCircumference = 2*PI*r;
        }
        __property float get_radius()
        {
                return fRadius;
        }
        //related getters and setters for other private data members...
};

getters and setters are useful for automatically updating related members, not for actually getting and setting the variable itself, that's what the = operator is for

But if you are keeping LOTS of circles, storing all the area, diameter and circumference is a bit excessive, as they can all be calculated quite easily when needed. All you have to STORE in the function is the radius.

Using getter/setter functions will allow you to CONTROL what values are set, and to hide the internal representation.

For example, if we produce a class like you have above, and then decide that we can actually find the right circle much faster by simply storing the radius [because it takes up 1/4 of the space, and using less memory means we can walk through more of them in the same amount of time, approximately 4 times faster in fact], and calculating the other components, then we have to change ALL the code that uses area, circumference and diameter. If on the other hand, you have a function getArea() that returns the area, we can implement the area calculation either as part of the setRadius() or as part of the getArea() function - more freedom, less dependancy on the class data structure itself.

And of course, if fArea is private, you can't use = to set it anyways.

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Mats