Implement the
operator ++(prefix), --(prefix), ++(postfix), --(postfix), in the
class Date
class Date
{
public:
Date(
int y=
0,
int m=
1,
int d=
1);
static bool leapyear(
int year);
int getYear()
const;
int getMonth()
const;
int getDay()
const;
friend ostream&
operator<<(ostream&,
const Date&);
};
You implementation should enable the usage like
this:
void f()
{
Date date(
2004,
2,
28);
cout <<
"date = " << date << endl;
cout <<
"++date = " << ++date << endl;
cout <<
"--date = " << --date << endl;
cout <<
"date++ = " << date++ << endl;
cout <<
"date-- = " << date-- << endl;
cout <<
"date = " << date << endl;
}
The output of f() should be:
date =
2004-
2-
28
++date =
2004-
2-
29
--date =
2004-
2-
28
date++ =
2004-
2-
28
date-- =
2004-
2-
29
date =
2004-
2-
28
提交时不需要提交
operator << 重载。
#include<iostream>
using namespace std;
class Date
{
public:
Date(
int y=
0,
int m=
1,
int d=
1);
static bool leapyear(
int year);
int getYear()
const;
int getMonth()
const;
int getDay()
const;
Date
operator++();
Date
operator++(
int x);
Date
operator--();
Date
operator--(
int x);
friend ostream&
operator<<(ostream&,
const Date&);
private:
int year;
int month;
int day;
};
#include<iostream>
#include<string>
#include"1001.h"
using namespace std;
ostream&
operator<<(ostream& os,
const Date& date)
{
os << date.getYear() <<
"-" << date.getMonth() <<
"-" << date.getDay();
return os;
}
void f3_1(
const Date& d)
{
Date date = d;
cout <<
"date = " << date << endl;
cout <<
"++date = " << ++date << endl;
cout <<
"--date = " << --date << endl;
cout <<
"date++ = " << date++ << endl;
cout <<
"date-- = " << date-- << endl;
cout <<
"date = " << date << endl;
cout << endl;
}
void f3()
{
Date date1, date2(
2004,
2,
28), date3(
2007,
2,
28),date4(
2000,
2,
28),date5(
99,
12,
31);
f3_1(date1);
f3_1(date2);
f3_1(date3);
f3_1(date4);
f3_1(date5);
}
int main()
{
f3();
return 0;
}
Date::Date(int y, int m, int d):year(y),month(m),day(d){}
bool Date::leapyear(int year)
{
if((year%400)==0||(year%4==0&&year%100!=0))
return true;
return false;
}
int Date::getYear() const
{
return year;
}
int Date::getMonth() const
{
return month;
}
int Date::getDay() const
{
return day;
}
Date Date::operator++()
{
day++;
int a[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int b[13]={0,31,29,31,30,31,30,31,31,30,31,30,31};
if(leapyear(year))
{
if(day>b[month]){
day=1;month++;
}
if(month>12){
month=1;year++;day=1;
}
}
else{
if(day>a[month]){
day=1;month++;
}
if(month>12){
month=1;year++;day=1;
}
}
return *this;
}
Date Date::operator++(int x)
{
Date temp(year,month,day);
day++;
int a[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int b[13]={0,31,29,31,30,31,30,31,31,30,31,30,31};
if(leapyear(year))
{
if(day>b[month]){
day=1;month++;
}
if(month>12){
month=1;year++;day=1;
}
}
else{
if(day>a[month]){
day=1;month++;
}
if(month>12){
month=1;year++;day=1;
}
}
return temp;
}
Date Date::operator--()
{
day--;
int a[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int b[13]={0,31,29,31,30,31,30,31,31,30,31,30,31};
if(leapyear(year))
{
if(day==0)
{
month--;
day=b[month];
}
if(month==0)
{
year--;
month=12;
day=31;
}
}
else
{
if(day==0)
{
month--;
day=a[month];
}
if(month==0)
{
year--;
month=12;
day=31;
}
}
return *this;
}
Date Date::operator--(int x)
{
Date temp(year,month,day);
day--;
int a[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int b[13]={0,31,29,31,30,31,30,31,31,30,31,30,31};
if(leapyear(year))
{
if(day==0)
{
month--;
day=b[month];
}
if(month==0)
{
year--;
month=12;
day=31;
}
}
else{
if(day==0)
{
month--;
day=a[month];
}
if(month==0)
{
year--;
month=12;
day=31;
}
}
return temp;
}
心得： （1）如果在类的声明构造函数里面有了默认参数，那么在定义的时候就不能够再写出参数了； （2）++的思路是：先让日期加一，然后判断是否是闰年，然后判断日期数目是否大于本月份的日期数目，然后再判断月份数目是否大于12；
if(leapyear(
year))
{
if(
day>b[
month]){
day=
1;
month++;
}
if(
month>
12){
month=
1;
year++;
day=
1;
}
}
（2） - -的思路是：先让日期减一，然后判断是否是闰年，然后判断日期数目是否等于0，然后再判断月份数目是否等于0；
if(leapyear(
year))
{
if(
day==
0)
{
month
day=b[
month];
}
if(
month==
0)
{
year
month=
12;
day=
31;
}
}
