C++中如何将operator==定义为类的成员函数

C++将operator==定义为类的成员函数

Duree.h

#ifndef _DUREE_H
#define _DUREE_H
class Duree{
 public:
 Duree(int heures = 0,int minutes = 0,int secondes = 0);
 bool estEgal(Duree const &b)const;
 bool operator==(Duree const& other);//如果把operator==作为类的成员函数,那么只需要一个参数就够了
 private:
 int m_heures;
 int m_minutes;
 int m_secondes;

};
#endif

Duree.cpp

#include<iostream>
#include "Duree.h"
using namespace std;
Duree::Duree(int heures,int minutes,int secondes):m_heures(heures),m_minutes(minutes),m_secondes(secondes){
 cout<<m_heures<<" "<<m_minutes<<" "<<m_secondes<<endl;
}
bool Duree::estEgal(Duree const& other)const{
 return (m_heures==other.m_heures && m_minutes == other.m_minutes && m_secondes == other.m_secondes);
}

bool Duree::operator==(Duree const& other){
 return estEgal(other);
}

Duree_Main.cpp

#include<iostream>
#include "Duree.h"
using namespace std;

int main(){
 Duree first(10,10,10),second(15,20);
 if(first == second)
 cout<< "Les durees sont identiques"<<endl;
 else
 cout<< "Les durees sont differents"<<endl;

 return 0;
}

编译运行

参考

https://stackoverflow.com/questions/23162870/c-bool-operator

C++对operator=进行重写

/*************************************************************************
	> File Name: copy1.cpp
	> Author: 
	> Mail: 
	> Created Time: 2020年06月17日 星期三 15时36分57秒
 ************************************************************************/

#include<iostream>
using namespace std;

class Example{
 std::string* ptr;
 public:
 Example():ptr(new std::string){}//new std::string返回的值是存储字符串的地址
 Example(const std::string& str):ptr(new std::string(str)){}
 Example(const Example& example):ptr(new std::string(example.content())){};
 ~Example(){delete ptr;}
 const std::string& content()const{return *ptr;}
 Example& operator= (const Example& x){
 cout<<"执行了"<<endl;
 delete ptr;//释放指针指向的字符串占用的内存
 ptr = new string(x.content());
 return *this;
 }
 Example operator+(const Example & rhs){
 return Example(content()+rhs.content());
 }

 void print_information()const{
 cout<< *ptr<<endl;
 }
};

int main(){
 Example bar1("hello");
 bar1.print_information();
 Example bar2("world");
 bar2.print_information();
 Example bar3 = Example(bar1);
 bar3.print_information();
 Example bar4 = bar2;
 bar4.print_information();

 Example foo("Exam");
 Example ba = Example("ple");
 foo = foo + ba;
 cout<<"foo's content:"<<foo.content()<<endl;


 
 return 0;
}

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总结

作者:久许原文地址:https://blog.csdn.net/jiuweideqixu/article/details/106780533

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