Question

用java编写point类，有两个属性xy，一个方法，distance（point p1，point p2.）计算两者的距离

Answer 1

Java程序：

class Point {
	protected double x;
	protected double y;
	
	public Point() {
		x = 0;
		y = 0;
	}
	
	public Point(double x, double y) {
		this.x = x;
		this.y = y;
	}
	
	public static double distance(Point p1, Point p2) {
		return Math.sqrt(Math.pow(p1.x - p2.x, 2) + Math.pow(p1.y - p2.y, 2));
	}
}
public class Main {
	public static void main(String[] args) {
		Point p1 = new Point(0, 0);
		Point p2 = new Point(1, 2);
		
		System.out.println("p1、p2两点之间的距离：" + Point.distance(p1, p2));
	}
}

运行测试：

p1、p2两点之间的距离：2.23606797749979

Answer 2

参考：
public class Strecke {
Punkt p1, p2;
Strecke (Punkt punkt1, Punkt punkt2) {
this.p1 = punkt1;
this.p2 = punkt2;
}
public Punkt mittelPunkt() {
return new Punkt ((p1.getX()+p2.getX())/2, (p1.getY()+p2.getY())/2);
}
public double abstand() {
return Math.sqrt(
(p1.getX() - p2.getX()) * (p1.getX() - p2.getX()) +
(p1.getY() - p2.getY()) * (p1.getY() - p2.getY())
);
}
static public void main (String args[]) {
Strecke s = new Strecke (new Punkt(2.0, 2.0), new Punkt(5.0, 6.0));
Punkt mp = s.mittelPunkt();
System.out.println ("Midpoint = (" + mp.getX() + "," + mp.getY() + ")");
double as = s.abstand();
System.out.println ("Length = " + as);
}
}