C++基础之拷贝构造函数

      拷贝构造函数是一种特殊的构造函数，它的形式参数就是本类对象的引用，作用是使用一个已经存在的对象去初始化另一个同类对象。

      因为该函数也是一种构造函数，所以其函数名与类名相同，并且该函数也没有返回值类型和返回值。该函数的唯一参数就是同类对象的引用。

      #include <iostream>#include <stdio.h>using namespace std;class MyDate{public:MyDate(int num=1 , int y=0, int m=0 , int d=0);MyDate(MyDate &temp) ;~MyDate();void SetDate(int n, int y, int m, int d) ;int getn(void);int gety(void);int getm(void);int getd(void);void MyPrint(void);protected:private:int num ;int MyYear ;int MyMonth ;int MyDay ;};MyDate::MyDate(int n, int y, int m, int d){num = n ;MyYear = y ;MyMonth = m ;MyDay = d ;}MyDate::MyDate(MyDate &temp){num = temp.num+1 ;MyYear = temp.MyYear+1 ;MyMonth = temp.MyMonth+1 ;MyDay = temp.MyDay+1 ;}MyDate::~MyDate(){}void MyDate::SetDate(int n , int y , int m , int d){num = n ;MyYear = y ;MyMonth = m ;MyDay = d ;}int MyDate::getn(void){return num;}int MyDate::gety(void){return MyYear ;}int MyDate::getm(void){return MyMonth ;}int MyDate::getd(void){return MyDay;}void MyDate::MyPrint(void){cout<<"Date"<<num<<":"<<MyYear<<"-"<<MyMonth<<"-"<<MyDay<<endl ;return ;}int main(void) {MyDate Date1(1,2010,8,12);MyDate Date2(Date1);Date1.MyPrint();Date2.MyPrint();return 0;}