// Lab 5: Date.h
#ifndef DATE_H
#define DATE_H
class Date
{
public:
Date( int = 1, int = 1, int = 2000 ); // default constructor
void print(); // print function
void setDate( int, int, int ); // set month, day, year
void setMonth( int ); // set month
void setDay( int ); // set day
void setYear( int ); // set year
int getMonth(); // get month
int getDay(); // get day
int getYear(); // get year
void nextday(int &,int &,int&);//Date of accumulation
/* Write a member function prototype for nextDay,
which will increment the Date by one day */
private:
int month; // 1-12
int day; // 1-31 (except February(leap year), April, June, Sept, Nov)
int year; // 1900+
bool leapYear(); // leap year
int monthDays(); // days in month
}; // end class Date
#endif
```c++
// Lab 5: Date.cpp
// Member-function definitions for class Date.
#include "Date.h"
#include <iostream>
using namespace std;
// include definition of class Date
Date::Date( int m, int d, int y )
{
setDate( m, d, y ); // sets date
} // end Date constructor
void Date::setDate( int mo, int dy, int yr )
{
setMonth( mo ); // invokes function setMonth
setDay( dy ); // invokes function setDay
setYear( yr ); // invokes function setYear
} // end function setDate
void Date::setDay( int d )
{
if ( month == 2 && leapYear() )
day = ( d <= 29 && d >= 1 ) ? d : 1;
else
day = ( d <= monthDays() && d >= 1 ) ? d : 1;
} // end function setDay
void Date::setMonth( int m )
{
month = m <= 12 && m >= 1 ? m : 1; // sets month
} // end function setMonth
void Date::setYear( int y )
{
year = y >= 1900 ? y : 1900; // sets year
} // end function setYear
int Date::getDay()
{
return day;
} // end function getDay
int Date::getMonth()
{
return month;
} // end function getMonth
int Date::getYear()
{
return year;
} // end function getYear
void Date::print()
{
cout << month << '-' << day << '-' << year << '\n'; // outputs date
} // end function print
/* c */
bool Date::leapYear()
{
if ( getYear() % 400 == 0 || ( getYear() % 4 == 0 && getYear() % 100 != 0 ) )
return true; // is a leap year
else
return false; // is not a leap year
} // end function leapYear
int Date::monthDays()
{
const int days[ 12 ] =
{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
return getMonth() == 2 && leapYear() ? 29 : days[ getMonth() - 1 ];
} // end function monthDays
//returns the maximum number of days in the current month
void nextday(int &day,int &month,int &year) {
day+= 1;
int maxday = monthDays();//调用monthDays会报错
//未定义标识符
if (month > maxday) {
month += 1;
day = 1;
}
if (month == 13) {
year++;
month = 1;
}
}
```c++
// Lab 5: DateTest.cpp
#include <iostream>
using namespace std;
#include "Date.h" // include definitions of class Date
int main()
{
const int MAXDAYS = 16;
Date d( 12, 24, 2004 ); // instantiate object d of class Date
// output Date object d's value
for ( int loop = 1; loop <= MAXDAYS; ++loop )
{
d.print(); // invokes function print
/* Write call to nextDay */
d.nextday();//nextday函数括号里面不知道该怎么引用，d.getDAY吗？
cout << " The next day will be:";
d.print();
} // end for
cout << endl;
} // end main
包含这个函数声明的头文件 添加进去了吗？
monthDays()是Date的私有成员函数，只可以在Date类中被调用，不可被外部调用。解决办法：把int monthDays(); 放到public里面