C++day04(类中特殊成员函数、匿名对象、友元、常成员函数和常对象、运算符重载)

1> 思维导图

2> 整理代码

代码：

算术运算符重载：

#include <iostream>

using namespace std;
class Person
{
    //全局函数实现运算符重载需要权限
    friend const Person operator+(const Person L,const Person R);
private:
    int a;
    int b;
public:
    Person() {}
    Person(int a,int b){
        this->a=a;
        this->b=b;
    }
    void show(){
        cout << "a=" << a <<"b=" << b<<endl;
    }
//    成员函数实现运算符重载
//    const Person operator+(const Person p)const{
//        Person temp;
//        temp.a=a+p.a;
//        temp.b=b+p.b;
//        return temp;
//    }
    const Person operator-(const Person p)const{
        Person temp;
        temp.a=a-p.a;
        temp.b=b-p.b;
        return temp;
    }
    const Person operator*(const Person p)const{
        Person temp;
        temp.a=a*p.a;
        temp.b=b*p.b;
        return temp;
    }
    const Person operator/(const Person p)const{
        Person temp;
        temp.a=a/p.a;
        temp.b=b/p.b;
        return temp;
    }

};
//全局函数实现运算符重载
const Person operator+(const Person L,const Person R){
    Person temp;
    temp.a=L.a+R.a;
    temp.b=L.b+R.b;
    return temp;
}
int main()
{
    Person p1(10,10);
    Person p2(10,20);
    Person p3=p1+p2;
    Person p4=p1-p2;
    Person p5=p1*p2;
    Person p6=p1/p2;
    p1.show();
    p2.show();
    p3.show();
    p4.show();
    p5.show();
    p6.show();
    return 0;
}

关系运算符重载：

#include <iostream>

using namespace std;
class Person
{
    //全局函数实现运算符重载需要权限
    friend bool operator>(const Person L,const Person R);
private:
    int a;
    int b;
public:
    Person() {}
    Person(int a,int b){
        this->a=a;
        this->b=b;
    }
    void show(){
        cout << "a=" << a <<"b=" << b<<endl;
    }

//    bool operator>(const Person p)const{
//        if(a>p.a && b>p.b){
//            return true;
//        }
//        return false;
//    }
    bool operator==(const Person p)const{
        if(a==p.a && b==p.b){
            return true;
        }
        return false;
    }
    bool operator<(const Person p)const{
        if(a<p.a && b<p.b){
            return true;
        }
        return false;
    }
    bool operator>=(const Person p)const{
        if(a>=p.a && b>=p.b){
            return true;
        }
        return false;
    }
    bool operator<=(const Person p)const{
        if(a<=p.a && b<=p.b){
            return true;
        }
        return false;
    }

};
//全局函数实现运算符重载
bool operator>(const Person L,const Person R){
    if(L.a>R.a && L.b>R.b)
    return true;
    return false;
}

int main()
{
    Person p1(10,10);
    Person p2(10,20);
    p1.show();
    p2.show();
    if(p2>p1){
        cout << "p2>p1" <<endl;
    }
    if(p2==p1){
        cout << "p2==p1" <<endl;
    }
    if(p2<p1){
        cout << "p2<p1" <<endl;
    }
    if(p2>=p1){
        cout << "p2>=p1" <<endl;
    }
    if(p2<=p1){
        cout << "p2<=p1" <<endl;
    }

    return 0;
}

赋值运算符重载

#include <iostream>

using namespace std;
class Person
{
    //全局函数实现运算符重载需要权限
    friend Person &operator+=(Person &L,const Person &R);
private:
    int a;
    int b;
public:
    Person() {}
    Person(int a,int b){
        this->a=a;
        this->b=b;
    }
    void show(){
        cout << "a=" << a <<"b=" << b<<endl;
    }
//    Person &operator+=(const Person p){
//        a+=p.a;
//        b+=p.b;
//        return *this;
//    }
    Person &operator-=(const Person p){
        a-=p.a;
        b-=p.b;
        return *this;
    }
    Person &operator*=(const Person p){
        a*=p.a;
        b*=p.b;
        return *this;
    }
    Person &operator/=(const Person p){
        a/=p.a;
        b/=p.b;
        return *this;
    }
    Person &operator%=(const Person p){
        a%=p.a;
        b%=p.b;
        return *this;
    }

};
//全局函数实现运算符重载
Person &operator+=(Person &L,const Person &R){
    L.a+=R.a;
    L.b+=R.b;
    return L;
}

int main()
{
    Person p1(10,10);
    Person p2(10,20);
    p1.show();
    p2.show();
//    cout << "+=";
//    p2+=p1;
//    p2.show();

//    cout << "-=";
//    p2-=p1;
//    p2.show();

//    cout << "*=";
//    p2*=p1;
//    p2.show();

//    cout << "/=";
//    p2/=p1;
//    p2.show();

    cout << "%=";
    p2%=p1;
    p2.show();

    return 0;
}

今日思维导图