2.15（几何：两点间距离）编写程序，提示用户输入两个点（x1，y1）和（x2，y2），然后显示两点间的距离。计算两点间距离的公式是。注意：可以使用Math.pow(a,0.5)来计算。 下面是一个运行示例：
Enter x1 and y1:1.5 -3.4
Enter x2 and y2:4 5
The distance between the two points is 8.764131445842194
2.15(Geometry: distance of two points) Write a program that prompts the user to enter two points (x1, y1) and (x2, y2) and displays their distance. The formula for computing the distance is 。Note you can use Math.pow(a,0.5) to compute. Here is a simple run:
Enter x1 and y1:1.5 -3.4
Enter x2 and y2:4 5
The distance between the two points is 8.764131445842194
参考代码：
package chapter02; import java.util.Scanner; public class Code_15 { public static void main(String[] args) { double x1,y1,x2,y2,PointDistance; Scanner PointInput; System.out.print("Enter x1 and y1 : "); PointInput = new Scanner(System.in); x1 = PointInput.nextDouble(); y1 = PointInput.nextDouble(); System.out.print("Enter x2 and y2 : "); PointInput = new Scanner(System.in); x2 = PointInput.nextDouble(); y2 = PointInput.nextDouble(); PointDistance = Math.pow(Math.pow(x2-x1, 2) + Math.pow(y2-y1, 2), 0.5); System.out.println("The distance between the two points is " + PointDistance); PointInput.close(); } } 结果显示： Enter x1 and y1 : 1.5 -3.4 Enter x2 and y2 : 4 5 The distance between the two points is 8.764131445842194 Process finished with exit code 0