85.深浅拷贝

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstring>
using namespace std;

//默认拷贝构造只是值传递,对于数据有效,对于指针则是同一个指向,需要重写一下拷贝构造
//类的内部有指针分配内存,需要深拷贝,否则需要浅拷贝
class mystring
{
public:
    char *pstr;
    int length;

public:
    mystring(char *str)
    {
        this->length = strlen(str) + 1;
        this->pstr = new char[this->length]{ 0 };
        strcpy(this->pstr, str);//初始化
    }

    //拷贝构造
    mystring(const mystring &mystr)
    {
        this->length = mystr.length;
        this->pstr = new char[this->length]{ 0 };
        strcpy(this->pstr, mystr.pstr);
    }


    void show()
    {
        cout << length << " " << (void *)pstr << "  " << endl;
    }
};


void main()
{
    mystring str1("gogogo");
    str1.show();
    //浅拷贝指向的地址都一样
    mystring str2(str1);
    str2.show();
    cin.get();
}