8.cpp

一系列的c++例子 一步一步由浅入深 有 聊天室

//例1.8  该程序的功能是已知两点坐标，求出两点的距离。
#include <iostream.h>
#include <math.h>
class Point
{
public:
Point(double xx, double yy) { x=xx; y=yy; }
void Getxy();
friend double Distance(Point &a, Point &b); //友元函数
private:
double x, y;
};
void Point::Getxy()
{
cout<<"("<<x<<","<<y<<")"<<endl;
}
double Distance(Point &a, Point &b)
{
double dx = a.x - b.x;
double dy = a.y - b.y;
return sqrt(dx*dx+dy*dy);
}
void main()
{
Point p1(3.0, 4.0), p2(6.0, 8.0);
p1.Getxy();
p2.Getxy();
double d = Distance(p1, p2);
cout<<"Distance is"<<d<<endl;
}