这个赋值运算符可以吗，复制ctor可以吗?

问题描述

我想知道这个赋值运算符和复制构造函数是否正常.我刚开始上课.在删除后将指针设置为NULL也是一种好习惯还是毫无意义.

#include <iostream>
#include <string>

using std::cout;
using std::endl;
using std::cin;

class stickfigure
{
public:
    stickfigure(int j)
    : test(new int(j))
    {}
    stickfigure(const stickfigure& ref)
    : test(new int(*ref.test))
    {}
    stickfigure& operator = (const stickfigure& ref)
    {
        if (this != &ref)
        {
            delete test;
            test = new int(*ref.test);
        }
        return *this;
    }
    virtual ~stickfigure(){ delete test;}
    void print() const{cout << *test << endl;}
private:
    int* test;
};

int main(int argc, char** argv)
{
    stickfigure stickone(76);
    stickone.print();
    // copy
    stickfigure sticktwo(stickone);
    sticktwo.print();
    // assignment
    stickfigure stickthree = sticktwo;
    stickthree.print();
}

解决方案

I was wondering if this assignment operator and copy constructor looks ok. I am just starting classes. also would it be good practice or pointless to set the pointer to NULL after delete.

#include <iostream>
#include <string>

using std::cout;
using std::endl;
using std::cin;

class stickfigure
{
public:
    stickfigure(int j)
    : test(new int(j))
    {}
    stickfigure(const stickfigure& ref)
    : test(new int(*ref.test))
    {}
    stickfigure& operator = (const stickfigure& ref)
    {
        if (this != &ref)
        {
            delete test;
            test = new int(*ref.test);
        }
        return *this;
    }
    virtual ~stickfigure(){ delete test;}
    void print() const{cout << *test << endl;}
private:
    int* test;
};

int main(int argc, char** argv)
{
    stickfigure stickone(76);
    stickone.print();
    // copy
    stickfigure sticktwo(stickone);
    sticktwo.print();
    // assignment
    stickfigure stickthree = sticktwo;
    stickthree.print();
}

解决方案

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