Question

编写一个表示平面上点的类MyPoint，成员变量和成员方法为：

doublex,y,表示x和y坐标
MyPoint（） MyPoint（double x,double y)
double distance(MyPoint mp),求两点之间的距离
创建两个MyPoint对象，坐标分别为（3,4）和（8,9），并通过对象求这两点之间的距离

Answer 1

public class Mypoint
{
double x, y;
public Mypoint( double x0, double y0 ){
x = x0;
y = y0;
}
double distance( Mypoint mp )
{
return Math.sqrt( ( x - mp.x) * (x - mp.x ) + (y-mp.y) * (y-mp.y) );
}
public static void main(String[] args)
{
Mypoint a = new Mypoint( 3, 4 );
Mypoint b = new Mypoint( 8, 9 );
System.out.println( a.distance( b ));
}
}

Answer 2

public class Mypoint
{
double x, y;
public Mypoint( double x0, double y0 ){
x = x0;
y = y0;
}
double distance( Mypoint mp )
{
return Math.sqrt( ( x - mp.x) * (x - mp.x ) + (y-mp.y) * (y-mp.y) );
}
public static void main(String[] args)
{
Mypoint a = new Mypoint( 3, 4 );
Mypoint b = new Mypoint( 8, 9 );
System.out.println( a.distance( b ));
}
}

Answer 3

根据公式求距离呀！