Counter example from the book C how to program.

Count.cpp

// Implementation file for Count class
#include <iostream>
#include "Count.h"
using std::cout;
using std::endl;


// set value of private data member x
void Count::setX(int value){
    x = value;
}

// print value of private data member x
void Count::print(){
    cout << x << endl;
}

Count.h

// Definition file for Count class

// class Count definition
#ifndef COUNT_H
#define COUNT_H

class Count{
    public:
         void setX(int);
         void print();
    private:
         int x;
};

#endif

main.cpp

#include <iostream>

using std::cout;
using std::endl;

#include "Count.h"

int main(){
    Count counter; // create counter object
    Count *counterPtr = &counter; // create a pointer to counter
    Count &counterRef = counter; //  create a reference to counter

    cout << "Set x to 1 and print using the object's name: ";
    counter.setX( 1 ); // set data member x to 1
    counter.print();  //  call member function print

    cout << "Set x to 2 and print using a reference to that object: ";
    counterRef.setX( 2 ); // set data member x to 1
    counterRef.print();  //  call member function print

    cout << "Set x to 3 and print using a pointer to that object: ";
    counterPtr->setX( 3 ); // set data member x to 1
    counterPtr->print();  //  call member function print

    return 0;
}