A trivial “cylinder”, non-OO

A cylinder is defined by its radius and it height. You are familiar with this:

#include <iostream.h>

#define PI 3.141592654

struct cylinder

{

float radius;

float height;

};

int main()

{

float volume;

struct cylinder c;

c.radius = 2.;

c.height = 1.;

volume = PI*c.radius*c.radius * c.height;

cout << "volume is " << volume << endl;

return 0;

}

You use a struct to group several simple entities to a more complex entity.

But you still have to know how to use that information to, say, calculate the volume.