运算符重载(个人学习笔记黑马学习)

1、加号运算符重载

#include <iostream>
using namespace std;
#include <string>//加号运算符重载
class Person {
public://1、成员函数重载+号//Person operator+(Person& p) {//	Person temp;//	temp.m_A = this->m_A + p.m_A;//	temp.m_B = this->m_B + p.m_B;//	return temp;//}int m_A;int m_B;
};//2、全局函数重载+号 
Person operator+(Person &p1,Person &p2) {Person temp;temp.m_A= p1.m_A + p2.m_A;temp.m_B = p1.m_B + p2.m_B;return temp;
}//函数重载的版本
Person operator+(Person& p1, int num) {Person temp;temp.m_A = p1.m_A + num;temp.m_B = p1.m_B + num;return temp;
}void test01() {Person p1;p1.m_A = 10;p1.m_B = 10;Person p2;p2.m_A = 10;p2.m_B = 10;//成员函数重载本质调用//Person p3 = p1.operator+(p2);//全局函数重载本质调用//Person p3 = operator+(p1, p2);//运算符重载 也可以发生函数重载Person p4 = p1 + 100;// Person + intcout << "p4.m_A = " << p4.m_A << endl;cout << "p4.m_B = " << p4.m_B << endl;Person p3 = p1 + p2;cout << "p3.m_A = " << p3.m_A << endl;cout << "p3.m_B = " << p3.m_B << endl;
}int main() {test01();system("pause");return 0;
}

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2、左移运算符重载

#include <iostream>
using namespace std;
#include <string>//左移运算符class Person {friend ostream& operator<<(ostream& cout, Person& p);
//public:public:Person(int a, int b) {m_A = a;m_B = b;}
private://利用成员函数重载 左移运算符 p,operator<<(cout) 简化版本p<<cout//不会利用成员函数重载<<运算符 因为无法实现 cout在左侧/*void operator<<(cout) {}*/int m_A;int m_B;};
//只能利用全局函数重载左移运算符
ostream& operator<<(ostream& cout, Person& p) {//本质：operator<<(cout,p)  简化cout<<pcout << "m_A = " << p.m_A << " m_B = " << p.m_B ;return cout;}void test01() {/*Person p;p.m_A = 10;p.m_B = 10;*/Person p(10,10);cout << p << endl;;
}int main() {test01();system("pause");return 0;
}

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3、递增运算符重载

#include <iostream>
using namespace std;
#include <string>//递增运算符重载//自定义整型
class MyInteger {friend ostream& operator<<(ostream& cout, MyInteger myint);public:MyInteger() {m_Num = 0;}//重载前置++运算符  返回引用为了一直对一个数据进行递增操作MyInteger& operator++() {//先进行++运算  在将自身做返回m_Num++;return *this;}//重载后置++运算符//void operator++(int) int代表占位参数，可以用于区分前置和后置MyInteger operator++(int) {//先 记录当前结果MyInteger temp = *this;//后递增m_Num++;//最后将记录结果做返回return temp;}private:int m_Num;
};//重载<<运算符
ostream& operator<<(ostream& cout, MyInteger myint) {cout << myint.m_Num;return cout;
}void test01() {MyInteger myint;//cout << ++myint << endl;cout << ++(++myint) << endl;cout << myint << endl;
}void test02() {MyInteger myint;cout << myint++ << endl;cout << myint << endl;
}int main() {//test01();test02();system("pause");return 0;
}

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4、赋值运算符重载

#include <iostream>
using namespace std;
#include <string>//赋值运算符重载
class Person {
public:Person(int age) {m_Age=new int(age);}~Person() {if (m_Age != NULL) {delete m_Age;m_Age = NULL;}}//重载 赋值运算符Person& operator=(Person& p) {//编译器提供浅拷贝//m_Age = p.m_Age;//应该先判断是否有属性在堆区，如果有先释放干净，融合再深拷贝if (m_Age != NULL) {delete m_Age;m_Age = NULL;}//深拷贝m_Age = new int(*p.m_Age);return *this;}int* m_Age;
};void test01() {Person p1(18);Person p2(20);Person p3(30);p3 = p2 = p1;//赋值操作cout << "p1的年龄为：" << *p1.m_Age << endl;cout << "p2的年龄为：" << *p2.m_Age << endl;cout << "p3的年龄为：" << *p3.m_Age << endl;}int main() {test01();system("pause");return 0;
}

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5、关系运算符重载

#include <iostream>
using namespace std;
#include <string>//重载关系运算符class Person {
public:Person(string name, int age) {m_Name = name;m_Age = age;}//重载关系运算符==bool operator== (Person& p) {if (this->m_Name == p.m_Name && this->m_Age == p.m_Age) {return true;}return false;}//重载关系运算符!=bool operator!= (Person& p) {if (this->m_Name == p.m_Name && this->m_Age == p.m_Age) {return false;}return true;}string m_Name;int m_Age;
};void test01() {Person p1("Tom", 18);Person p2("Tom", 18);if (p1 == p2) {cout << "p1和p2是相等的" << endl;}else {cout << "p1和p2是不相等的" << endl;}if (p1 != p2) {cout << "p1和p2是不相等的" << endl;}else {cout << "p1和p2是相等的" << endl;}}int main() {test01();system("pause");return 0;
}

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6、函数调用运算符重载

#include <iostream>
using namespace std;
#include <string>//函数调用运算符重载//打印输出类
class MyPrint {
public://重载函数调用运算符void operator()(string test){cout << test << endl;}
};void test01() {MyPrint myPrint;myPrint("hello world");//由于使用起来非常类似于函数调用 因此称为仿函数}//仿函数非常灵活，没有固定的写法
//加法类class MyAdd {
public:int operator()(int num1, int num2) {return num1 + num2;}
};void test02() {MyAdd myadd;int ret=myadd(100, 100);cout << "ret = " << ret << endl;//匿名函数对象cout << MyAdd()(100, 100) << endl;
}int main() {//test01();test02();system("pause");return 0;
}