C++学习之路 ： class练习

需求：

1.作业：写一个Date类

a)      数据成员：year/month/day   ok

b)     提供两个构造函数   ok

c)      实现功能setDate设置日期   ok

d)     把时间设定为今天 setToday();   ok

e)      toString()  打印格式：2009/7/31    ok

f)       toFormatString：对于月份采用英文 September 19 2014 ok

g)      isLeapYear() 判断是否是闰年  ok

h)     calDayOfYear() 计算该日期是当年的第几天（注意闰年）   ok

i)        写一个全局的函数int differenceDate(const Date &d1, const Date &d2);比较两个日期的差异（d1 - d2）， 可以写为static函数 ok

j)        写一个static函数today()，返回代表今天的Date对象。

#include <iostream>
#include <string>
#include <vector>
#include <time.h>
#include <stdlib.h>
#include <stdio.h>

#define ERR_EXIT(m) 
    do { 
        perror(m);
        exit(EXIT_FAILURE);
    }while(0)

using namespace std;




class Date
{
    private :
        int year_;
        int month_ ;
        int day_;
    public :
        

            Date() :
                 year_(2014), month_(1), day_(1)  
             {}
        
             Date(int year, int month,  int day) :
                 year_(year), month_(month),  day_(day) 

             {
             }

        void setDate(int year, int  month,int day)
        {
            year_ = year ;
            month_ = month ;
            day_ = day ;
        } ;
        
        int getYear() const
        {
            return year_;
        }
        
        int getmonth() const
        {
            return month_ ;
        }

        int getDay() const
        {
            return day_ ;
        }

        int whatDay()
        {
            time_t t;
            t = time(NULL) ;
            struct tm* now = localtime(&t) ;
            int day = now->tm_yday;

            return day ;
        }

        void setToday()
        {
            time_t t;
            t = time(NULL);
            struct tm* now = localtime(&t) ;
            
            year_ = 1900 + now->tm_year;
            
            month_ = 1 + now->tm_mon ;
            day_ = now->tm_mday ;

           printf("local time is %s", asctime(now));
        }
        
        void toString()
        {
            cout << year_ << "/" << month_ << "/" << day_ << endl;
        } 

        void toFormatString()
        {
            switch (month_)
            {
                case 1: cout << "January " ; break ;
                case 2: cout << "February " ; break;
                case 3: cout << "March " ; break;
                case 4: cout << "April " ; break;
                case 5: cout << "May " ; break;
                case 6: cout << "June " ; break ;
                case 7: cout << "July" ; break; 
                case 8: cout << "August" ; break ;
                case 9: cout << "September" ;break;
                case 10: cout << "October" ;break;
                case 11: cout << "November" ; break;
                case 12: cout << "December" ;break;
                default :  ERR_EXIT("月份输入错误") ;break;
            }
            cout << day_ << " " << year_ <<endl;

        }
        bool isLeapYear() const 
        {
           return (year_ % 400 == 0) || (year_ % 4 == 0 && year_ % 100 != 0) ;
        }

        int calDayOfYear() const
        {
            int sum = 0;
            if(isLeapYear())
            {
                int sign[13] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31} ;
                for(int i = 1; i < month_; i++)
                {
                    cout << "进入闰年循环" << endl;
                    sum += sign[i] ;
                }

            }else
            {
                int sign[13] = {0,31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31} ;
                for(int i = 1; i < month_; i++)
                {
                    cout << "进入非闰年循环" << endl;
                    sum += sign[i] ;
                }
                
            }
            sum += day_ ;
            
            return sum ;
        }
} ;


bool isLeapYear(int year)
{
    return (year % 400 == 0) || (year % 4 == 0 && year % 100 != 0) ;
}

static int differenceDate(const Date &d1, const Date &d2)
{
    int temp(0);
    int sum(0) ;
    int year1 = d1.getYear() ;
    int year2 = d2.getYear() ;

    if( year1 > year2)
    {
        for (int i = year2; i < year1; i++) {
             if(isLeapYear(i))
             {
                sum += 366 ;
             }else
             {
                sum += 365 ;
             }
        }
        sum += d2.calDayOfYear() ;
        sum -= d1.calDayOfYear() ;

    }else if(year1 == year2)
    {
        sum = d1.calDayOfYear() - d2.calDayOfYear() ;
        if(sum < 0)
        {
            sum = -sum;
        }
    }else
    {
        for (int i = year1; i < year2; i++) {
            if(isLeapYear(i))
            {
                sum += 366;
            }else
            {
                sum += 365;
            }
            sum += d2.calDayOfYear() ;
            sum -= d1.calDayOfYear() ;
        }
    }

    return sum ;
}

static Date toDay(Date &kong)
{
    kong.setToday() ;
    return kong;
}

int main(int argc, const char *argv[])
{
    Date test;    
    //test.setToday() ;
    cout << "设置前-----------------" << endl;
    test.toString() ;
    test.setDate(2014, 9, 20) ;
    cout << "设置后-----------------" << endl;
    test.toString() ;
    cout << "toFormatString" << endl;
    test.toFormatString() ;
    cout << "isLeapYear" << endl;
    if(test.isLeapYear()) 
        cout << "是闰年" << endl ;
    else
        cout << "不是闰年" << endl;
    cout << "calDayOfYear " << endl;
    int num = test.calDayOfYear() ;
    cout << "第 "<< num << "天" <<endl;
    
    cout<< "----whatDay()----" << endl;
    int day = test.whatDay() ;
    cout << day << endl;
    
    Date d1(2002, 1, 1) ;
    Date d2(2001, 1, 1) ;
    int dif;
    dif = differenceDate(d1, d2) ;
    
    cout << "-----differenceDate--------" << endl ;
    cout << dif << endl;
    return 0;
}

缺少一个 判断函数检验  输入的年月日是否非法。   其他功能均已实现