Chapter 1 Examples

1. Sum

import java.util.Scanner;

public class Hekko {
    
    
    public static void main(String args[]){
    
    
        System.out.println("输入若干个数，每输入一个数回车确认");
        System.out.println("输入0表示结束");
        Scanner reader =new Scanner(System.in);
        double sum=0;
        double x=reader.nextDouble();
        while(x!=0){
    
    
            sum=sum+x;
            x=reader.nextDouble();
        }
        System.out.println("sum="+sum);
    }
}

split line

---

---

2. Find the maximum

split line

---

---

3. Find the perimeter and area of ​​the triangle

package Redhur.demo;

import java.text.DecimalFormat;
import java.util.Scanner;

public class Hekko {
    
    
    public static void main(String args[]){
    
    
        double a,b,c;
        Scanner scan =new Scanner(System.in);
        System.out.print("请输入三角形三边值，空格隔开");
        a=scan.nextDouble();
        b=scan.nextDouble();
        c=scan.nextDouble();
        double C=a+b+c;
        double p=(a+b+c)/2;
        double S=Math.sqrt(p*(p-a)*(p-b)*(p-c));
        DecimalFormat precision=new DecimalFormat("0.00");
        String result="三条边分别为"+a+","+b+","+c+"的三角形\n"
                +"周长="+precision.format(C)+"\n"
                +"面积="+precision.format(S);
        System.out.print(result);
    }
}