Java学习第39天2020/8/13

一.
import java.util.Scanner;
public class point {
	Scanner input=new Scanner(System.in);
	private double x,y,z;
	public void in()
	{
		x=input.nextDouble();y=input.nextDouble();z=input.nextDouble();
	}
	public void out(){
		System.out.println("("+x+","+y+","+z+")");
	}
	public void get()
	{
		System.out.println("x="+x+"  "+"y="+y+"  "+"z="+z+"  ");
	}
	public void distance()
	{
		double p=x*x+y*y+z*z;
		System.out.println("到原点的距离是："+Math.sqrt(p));
	}
	public static void main(String []args) {
		point m=new point();
		m.in();
		m.out();
		m.get();
		m.distance();
	}
}

 

math.sqrt(double n);//其中n是被开方的数

如要给m开n次方就用：
java.lang.StrictMath.pow(m,1.0/n);

import java.util.Scanner;
public class point extends line{
	Scanner input=new Scanner(System.in);
	private double x,y,z;
	public void in()
	{
		x=input.nextDouble();y=input.nextDouble();z=input.nextDouble();
	}
	public void out(){
		System.out.println("("+x+","+y+","+z+")");
	}
	public double get_x()
	{
		return x;
	}
	public double get_y()
	{
		return y;
	}
	public double get_z()
	{
		return z;
	}
	public void distance()
	{
		double p=x*x+y*y+z*z;
		System.out.println("到原点的距离是："+Math.sqrt(p));
	}
	
	}



public class line {
    public static void main(String []args) {
        point []a=new point[2];
        System.out.println("输入两点的坐标：");
        for(int i=0;i<2;i++)
        {
            a[i]=new point();
        }
        for(int i=0;i<2;i++) {
        a[i].in();}
        double l=Math.pow(a[0].get_x()-a[1].get_x(), 2)+Math.pow(a[0].get_y()-a[1].get_y(), 2)+Math.pow(a[0].get_z()-a[1].get_z(), 2);
        System.out.println("两点之间的距离为："+Math.sqrt(l));
        }
}

 二.math.pow(x,2)

 math.sqrt(l);

三.例题