newclockimp.cpp

C++编成数据结构与程序设计方法 D.S.Malk编著

//Implementation file newClock.cpp

#include <iostream>
#include "newClock.h"

using namespace std;

//overload the pre-increment operator
clockType clockType::operator++()
{
    sec++;  				//Step a

	if (sec > 59)  			//Step b
	{
		sec = 0;			//Step b.1

		min++;    			//Step b.2

		if (min > 59)		//Step b.3
		{
			min = 0;		//Step b.3.1

			hr++;			//Step b.3.2

			if (hr > 23)		//Step b.3.3
				hr = 0;		//Step b.3.3.1
		}
	}
   
	return *this;   		//Step c
}

//overload the equality operator
bool clockType::operator==(const clockType& otherClock) const
{
	return(hr == otherClock.hr && min == otherClock.min
		   && sec == otherClock.sec);
}

//overload the equality operator
bool clockType::operator!=(const clockType& otherClock) const
{
	return ( !(*this == otherClock));
}


//overload the less than or equal to operator
bool clockType::operator<=(const clockType& otherClock) const
{
   return((hr < otherClock.hr) ||
	    (hr == otherClock.hr && min < otherClock.min) ||
	    (hr == otherClock.hr && min == otherClock.min &&
		         sec <= otherClock.sec));
}

//constructor with parameters
clockType::clockType(int hours, int minutes, int seconds)
{
	if (0 <= hours && hours < 24)
		hr = hours;
	else 
		hr = 0;

	if (0 <= minutes && minutes < 60)
		min = minutes;
	else 
		min = 0;

	if (0 <= seconds && seconds < 60)
		sec = seconds;
	else 
		sec = 0;
}

void clockType::setTime(int hours, int minutes, int seconds)
{
	if (0 <= hours && hours < 24)
		hr = hours;
	else 
		hr = 0;

	if (0 <= minutes && minutes < 60)
		min = minutes;
	else 
		min = 0;

	if (0 <= seconds && seconds < 60)
		sec = seconds;
	else 
		sec = 0;
}

void clockType::getTime(int& hours, int& minutes, int& seconds) const
{
	hours = hr;
	minutes = min;
	seconds = sec;
}

//overload the stream insertion operator
ostream& operator <<  (ostream& osObject, const clockType& timeOut)
{
	if (timeOut.hr < 10)
		osObject << '0';
	osObject << timeOut.hr << ':';
	
 	if (timeOut.min < 10)
		osObject << '0';
	osObject << timeOut.min << ':';
	
	if (timeOut.sec < 10)
		osObject << '0';
	osObject << timeOut.sec;

	return osObject;	//return the ostream object
}

   //overload the stream extraction operator
istream& operator >>  (istream& isObject, clockType& timeIn)
{
	char ch;

	isObject >> timeIn.hr;	  //Step a
	isObject.get(ch);         //Step b; read and discard :
	isObject >> timeIn.min;   //Step c
	isObject.get(ch);         //Step d; read and discard :
	isObject >> timeIn.sec;   //Step e

	return isObject;		  //Step f
}