深拷贝和浅拷贝

C++对于指针型成员变量有浅拷贝和深拷贝之分

#include <string>#include<iostream>using namespace std;class Person{public:    Person(){ cout << "Person()" << endl; }    Person(string name, int age)        :name(name), age(age)    {        ptr = new int;    }    //拷贝构造函数    Person(const Person &p)    {        cout << "Person(const Person&)" << endl;        name = p.name;        age = p.age;        //p.age++;//只读，不能改        //浅拷贝        //ptr = p.ptr;        //深拷贝        int *new_ptr = new int;        if (p.ptr != NULL)            *new_ptr = *p.ptr;        ptr = new_ptr;    }    void out()    {        cout << "myname:" << name << endl;        cout << "myage:" << age << endl;        cout << "*ptr:" << *ptr << endl;        cout << "-------------------" << endl;    }    int *ptr;private:    string name;    int age;};int main(void){    Person p("zhangsan", 30);    *p.ptr = 111;    Person p2(p);//1.调用拷贝构造函数方式一    *p2.ptr = 222;    p.out();    p2.out();    Person p3 = p;//2.调用拷贝构造函数方式二    *p3.ptr = 333;    p.out();    p2.out();    p3.out();    Person p4;    p4 = p;//调用赋值构造函数    p4.out();    return 0;}