cc22a_demo_c++重载自增自减操作符-代码示范

cc22a_demo_c++重载自增自减操作符-代码示范

#define  _CRT_SECURE_NO_WARNINGS

#include <iostream>

using namespace std;

class String

{

public:

    String(char const *chars="");

    String(String const &str);

    ~String();

    void display() const;

    String &operator++();//前加加  返回引用

    String const operator++(int);//后加加，返回拷贝

    String &operator--();

    String const operator--(int);

private:

    char *ptrChars;

};

String &String::operator++()

{

    for (std::size_t i = ; i < std::strlen(ptrChars); ++i)

    {

        ++ptrChars[i];

    }

    return *this;

}

String const String::operator++(int n)  //int自动设置为0

{

    String copy(*this);

    ++(*this);

    return copy;

}

String::String(char const *chars)

{

    chars = chars ? chars : "";

    ptrChars = new char[std::strlen(chars)+];

    std::strcpy(ptrChars,chars);

}

String::String(String const &str)

{

    ptrChars = new char[std::strlen(str.ptrChars) + ];

    std::strcpy(ptrChars,str.ptrChars);

}

String::~String()

{

    delete[] ptrChars;

}

void String::display() const

{

    cout << ptrChars << endl;

}

int main()

{

    int x = ;

    x++;

    ++x;

    //cout << x << endl;

    String s("ABC");

    s.display();

    ++s;

    s.display();

    ++s;

    s.display();

    cout << endl;

    String str1("ABC");

    str1.display();

    String str2(++str1);

    str2.display();

    String str3(str1++);

    str3.display();

    str1.display();

//    cout << "hello" << endl;

    system("pause");

    return ;

}