cpp31.cpp

C++参考书

// Coded by plusir -- Jan.05.2003.
// Standard C++ Bible -- (P343-11-31)

#include <iostream>
#include <string>
using namespace std ;

class Date
{
	public:
		Date( int = 0, int = 0, int = 0 ) ;
		Date( const Date & ) ;
		~Date( void ) ;
		void display( void ) const ;

	private:
		int month ;
		int day ;
		int year ;
		char *monthName ;
} ;

Date::Date( int m, int d, int y )
{
	static char *mos[] = {
		"January",
		"February",
		"March",
		"April",
		"May",
		"June",
		"July",
		"August",
		"Septermber",
		"October",
		"November",
		"December"
	} ;

	month = m ;
	day = d ;
	year = y ;

	if ( m != 0 ) {
		monthName = new char[strlen( mos[m - 1] ) + 1] ;
		strcpy( monthName, mos[m - 1] ) ;
	}
	else
		monthName = NULL ;
}

Date::Date( const Date &dt )
{
	month = dt.month ;
	day = dt.day ;
	year = dt.year ;

	if ( dt.monthName != NULL ) {
		monthName = new char[strlen( dt.monthName ) + 1] ;
		strcpy( monthName, dt.monthName ) ;
	}
	else
		monthName = NULL ;
}

Date::~Date( void )
{
	delete [] monthName ;
}

void Date::display( void ) const
{
	if ( monthName != NULL )
		cout << monthName << ' ' << day << ", " << year << endl ;
}

int main()
{
	Date birthday( 6, 24, 1940 ) ;
	birthday.display() ;

	Date newDay = birthday ;
	newDay.display() ;

	Date lastDay( birthday ) ;
	lastDay.display() ;

	return 0 ;
}