Learning: the object class and - operator overloading

What is operator overloading?

Operator overloading concepts: the existing operators are redefined, giving it another function, to accommodate different data types

For individuals learn feeling here is, more than a way to customize the way that it calculates, to automatically effect a corresponding operator through the operation similar syntactic sugar +

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The + operator overloading:

Action: implement two types of custom data adding operation

In which the + operator overloading, we can be defined in two ways, one is a member function to perform , there is a global function is achieved

The same call, there are two methods, the following code is reflected

Sample code:

#include<iostream>
#include<string>

using namespace std;

class Person{
public:

    //成员函数实现 + 号运算符重载
    //Person operator+(Person &p1) {
    //  Person temp;
    //  temp.age = this->age + p1.age;
    //  return temp;
    //}

public:
    int age;
};

//全局函数 实现+号运算符重载
Person operator+(Person &p1, int val) {
    Person temp;
    temp.age = p1.age + val;
    return temp;
}

int main() {
    Person p1;
    p1.age = 20;
    //Person p2 = p1.operator+(p1); //调用方式有两种，这是第一种
    Person p2 = p1 + 10;//这是第二种调用方式
    cout << p2.age << endl;
    system("pause");
    return 0;
}

Summary 1: For the built-in data type of an expression is unlikely to change operator

Summary 2: Do not abuse operator overloading