派生与继承

#include<iostream>

#include<cmath>

using namespace std;

class Point

{

private:

int x,y;

public:

Point(int a=0,int b=0){SetPoint(a,b);}

void SetPoint(int a,int b)

{

x=a;

y=b;

}

int GetX(){return x;}

int GetY(){return y;}

void Print()

{

cout<<"开始点："<<'['<<x<<','<<y<<"],";

}

};

class Line:public Point

{

private:

Point EndPoint;

public:

Line(int a,int b,int c,int d):Point(a,b),EndPoint(c,d){} //EndPoint组合成员

void Print()

{

Point::Print();

cout<<"结束点：["<<EndPoint.GetX()<<','<<EndPoint.GetY()<<']';

}

double Length()

{

double xx=Point::GetX()-EndPoint.GetX();

double yy=Point::GetY()-EndPoint.GetY();

double l=sqrt(xx*xx+yy*yy);

return l;

}

};

int main(){

Line line(1,1,10,10);

cout<<"Line line:";

line.Print();

cout<<"\n线line的长度：";

cout<<line.Length()<<endl;

return 0;

}