C++ 递增/递减运算符重载

作用： 通过重载递增运算符，实现自己的整型数据

总结： 前置递增返回引用，后置递增返回值

递增

#include<iostream>
using namespace std;class MyInteger {
private:int m_Num = 0;
public:friend ostream& operator<<(ostream& out, MyInteger myint);MyInteger() {m_Num = 0;}//重载前置++运算符  返回引用是一直对一个数据进行递增MyInteger& operator++() {//先++m_Num++;//再返回return *this;}//重载后置置++运算符MyInteger& operator++(int) {  //int代表占位参数，可以用于区分前置和后置递增//先返回MyInteger temp = *this; //记录当前本身的值，然后让本身的值+1，但是返回的是以前的值，达到先返回后++//再++m_Num++;return temp;}
};//重载左运算符
ostream& operator<<(ostream& out, MyInteger myint) {out << myint.m_Num;return out;
}void test01() {MyInteger myInt;cout << ++myInt << endl;cout << myInt << endl;
}void test02() {MyInteger myInt;cout << myInt++ << endl;cout << myInt << endl;
}int main()
{test01();test02();return 0;
}

递减

#include<iostream>
using namespace std;class MyInteger {
private:int m_num;
public:MyInteger() {m_num = 0;}//！！！！！！！ 必须用引用MyInteger &operator--() {//先++后运算m_num--;return *this;}//！！！！！！！ 必须用引用MyInteger &operator--(int) {//先传值后++MyInteger temp = *this;m_num--;return temp;}friend ostream& operator<<(ostream& out, MyInteger myint);
};//重载左运算符
ostream& operator<<(ostream& out, MyInteger myint) {out << myint.m_num;return out;
}void test01() {MyInteger myInt;cout << --(--myInt) << endl;cout << myInt << endl;
}void test02() {MyInteger myInt;cout << myInt-- << endl;cout << myInt << endl;
}int main()
{test01();test02();return 0;
}