C + + jobs-8

8-7 implements the operator of + +, while overloading the prefix

#include<bits/stdc++.h>using namespace std;class point{    public:    point(int a=0,int b=0):x(a),y(b){        }    point operator++ (){          x++;y++;          return *this;    }//前置     point operator++(int) {        point z=*this;        ++(*this);        return z;    }    point operator-- (){          x--;y--;          return *this;    }    point operator--(int) {        point z=*this;        --(*this);        return z;    }    void show(){        cout<<x<<" "<<y<<endl;    }    int x,y;}; int main(){    point k(1,1);    cout<<"k++ show:"<<endl;    (k++).show();    cout<<"++k show:"<<endl;    (++k).show();    cout<<"--k show:"<<endl;    (--k).show();    cout<<"k-- show:"<<endl;    (k--).show();}

8-8 observing the implementation of virtual functions and their derived conditions

#include<bits/stdc++.h>using namespace std;class BaseClass{    public:        virtual void fn1(){            cout<<"Base Class fn1"<<endl;        }        void fn2(){            cout<<"Base Class fn2"<<endl;        }}; class DerivedClass:public BaseClass{    public:        void fn1(){            cout<<"Derived Class fn1"<<endl;        }        void fn2(){            cout<<"Derived Class fn2"<<endl;        }};int main(){  DerivedClass    k;  BaseClass *k1=&k;  k1->fn1();  k1->fn2();  DerivedClass *k2=&k;  k2->fn1();  k2->fn2();}

8-10 overloading ' + ' on the friend function of Point

#include<bits/stdc++.h>using namespace std;class point{    public :    point(int a=0,int b=0):x(a),y(b){    }    friend point operator+( point k1, point k2);    void show();    private :        int x,y;}; void point::show(){    cout<<x<<" "<<y<<endl;}point operator+( point k1, point k2){    return point(k1.x+k2.x,k1.y+k2.y);}int main(){    point k1(1,2),k2(2,3),k3;    k3=k1+k2;    k1.show();    k2.show();    k3.show();}

C + + jobs-8