Question

2、设计并测试一个名为Rectangle的矩形类，

2、设计并测试一个名为Rectangle的矩形类，其属性为矩形的左下角与右上角两个点的坐标，能计算矩形的面积。

Answer 1

public class Rectangle {double chang,kuan;public double getArea(double chang,double kuan){return chang*kuan;}public double getPerimeter(double chang,double kuan){return (chang+kuan)*2;}public Rectangle(){}public Rectangle(double chang,double kuan){if(0

Answer 2

#include<iostream.h>
class car;
class boat{
private:
int weight;
public:
boat(int w):weight(w){}
friend int totalweight(boat b1,car c1);
};
class car{
private:
int weight;
public:
car(int w):weight(w){};
friend int totalweight(boat b1,car c1);
};
int totalweight(boat b1,car c1)
{
return b1.weight+c1.weight;
}
void main()
{
car c1(1000);
boat b1(2000);
cout<<totalweight(b1,c1)<<end1;
}