Time class implementation in cpp gotten from the book C How to program.

main.cpp

// program to run class Time
#include <iostream>
using std::cout;
using std::endl;

#include "Time.h"

int main(){
    Time t; // instantiate a Time object of class Time

    // output Time object t's initial values
    cout << "The initial universal time is ";
    t.printUniversal(); // 00:00:00
    cout << "\nThe initial standard time is  ";
    t.printStandard(); // 12:00:00 AM

    t.setTime(13, 14, 56 ); // change time

    // output Time object t's new values
    cout << "\n\nUniversal time after setTime is ";
    t.printUniversal(); // 13:14:56
    cout << "\nStandard time after setTime is ";
    t.printStandard(); // 1:14:56

    t.setTime(99, 99, 99); // attempt invalid settings

    // output t's values after specify ing invalid values
    cout << "\n\nAfter attempting invalid setting:"
            << "\nUniversal time: ";
    t.printUniversal(); // 00:00:00
    cout << "\nStandard time: ";
    t.printStandard(); // 12:00:00 AM
    cout << endl;

    return 0;
}

Time.cpp

// Member-function definitions for class Time
#include <iostream>
using std::cout;

#include <iomanip>
using std::setfill;
using std::setw;

#include "Time.h" // include definition of class Time from Time.h

// intialize data members to zero
Time::Time(){
    hour = minute = second = 0;
}

// set new time using universal time;
// To ensure data consistency all invalid values are set to 0
void Time::setTime( int h, int m, int s ){
    hour = ( h >= 0 && h < 24 ) ? h : 0; // validate hour
    minute = ( m >= 0 && m < 60 ) ? m : 0; // validate minute
    second = ( s >= 0 && s < 60 ) ? s : 0; // validate second
}

// Print time in universal time format
void Time::printUniversal(){
    cout << setfill( '0' ) << setw( 2 ) << hour << ":"
            << setw( 2 ) << minute << ":" << setw( 2 ) << second;
}

// Print time in standard time format
void Time::printStandard(){
    cout << ( ( hour == 0 || hour == 12 ) ? 12 : hour % 12 ) << ":"
            << setfill( '0' ) << setw( 2 ) << minute << ":" << setw( 2 )
            << second << ( hour < 12 ? " AM" : " PM" );
}

Time.h

// Declaration of class Time
// Member functions defined in Time.cpp

//  prevent multiple inclusion of header file
#ifndef TIME_H
#define TIME_H

// Time class definition
class Time{
    public:
        Time(); // constructor
        void setTime( int, int, int ); // set hour, minute and second
        void printUniversal(); // print time in universal-time format
        void printStandard();  // print time in standard-time format
    private:
        int hour;     // 0 - 23 (24-hour clock format)
        int minute;  // 0 - 59
        int second; //  0 - 59
}; // End class Time
#endif