指针与对象，指针与对象数组的联系与区别

来源：互联网发布：什么是网络安全策略编辑：程序博客网时间：2024/06/01 21:01
#include <iostream>using namespace std;class Recta{public: Recta(int len=10,int wid=10) {  length=len;  width=wid; } int getArea() {  return (length*width); } void disp()  {  cout<<"长是："<<length<<"  "<<"高是："<<width<<endl;  cout<<"面积："<<getArea()<<endl;//rec[i].getArea() 是错的，类是整体，不知道主函数里有什么 }private: int length,width;};int main(){ Recta rec[3]={ Recta(15,20), Recta(5,6), Recta(30,40) }; for(int i=0;i<3;i++) {  rec[i].disp(); } return 0;}//=====================================================================================#include <iostream>using namespace std;class Date{public: Date(int y,int m,int d);    void setDate(int y,int m,int d); void show();private: int year; int month; int day;};Date::Date(int y,int m,int d){ year=y; month=m; day=d;}inline void Date::setDate(int y,int m,int d){ year=y; month=m; day=d;}void Date::show(){ cout<<year<<"."<<month<<"."<<day<<endl;}int main(){ Date date(2013,2,25); date.show(); Date *dp; dp=&date;    //这的date是对象，不是指针，所以要用取地址符 dp->setDate(2012,11,16); dp->show(); return 0;}//=============================================================#include <iostream>using namespace std;class Date{public: Date(int y=2012,int m=7,int d=20);    void setDate(int y,int m,int d); void show();private: int year; int month; int day;};Date::Date(int y,int m,int d){ year=y; month=m; day=d;}inline void Date::setDate(int y,int m,int d){ year=y; month=m; day=d;}void Date::show(){ cout<<year<<"."<<month<<"."<<day<<endl;}int main(){ Date date[2]; Date *dp; date[0].setDate(2012,11,16); date[1].setDate(2013,2,25); dp=date;    //date[]是对象数组，date是起始地址，即指针，所以不用取地址符号。当把对象数组中的第i个赋给指针时，则用dp=&date[i] dp->show(); dp++; dp->show(); return 0;}