结束循环后系统输出 println 不起作用

Question

Hello guys (sorry bad english) I'm looking for answer on my own but I'm stuck and I don't know why it doesn't work :x (Please don't mock me, that's my first day on Java T_T )

I think that's obvious for you, but I have

"It looks like your post is mostly code; please add some more details."

so : when I type 0 and enter, code supposed to stop running the loop and show last lines, but I get nothing on the console :x

Here's the code

package fr.eni.demo;

import java.util.Scanner;

public class Cheque
{

    static double nbCheques = 0;
    static double total = 0;
    static double moyenne = 0;
    static double inf200 = 0;
    static double totalInf200 = 0;
    static double egalSup200 = 0;
    static double totalEgalSup200 = 0;
    static double numeroPlusPetit = 0;
    static double plusPetit = 0;
    static double numeroPlusGrand = 0;
    static double plusGrand = 0;


public static void main(String[] args)
{
    Scanner scan = new Scanner(System.in);
    System.out.println("Entrez le montant du chèque. 0 pour quitter.");
    double input = scan.nextDouble();
    
    while (input != 0);
    {
        nbCheques++;
        total = total + input;
            if (input < 200)
            {
                inf200++;
                totalInf200 = totalInf200 + input;
                plusPetit = input;          
                
                while (input < plusPetit)
                    {
                        plusPetit = input;
                        numeroPlusPetit = nbCheques;
                    }
            }
            else 
            {
                egalSup200++;
                totalEgalSup200 = totalEgalSup200 + input;
                plusGrand = input;  
                
                while (input > plusGrand)
                {
                    plusGrand = input;
                    numeroPlusGrand = nbCheques;
                }
            }
    } 
    moyenne = total/moyenne;
    System.out.println("Nombre(s) de chèque(s) : " + nbCheques);
    System.out.println("Montant total : " + total);
    System.out.println("Moyenne totale : " + moyenne);
    System.out.println("Chèque(s) inférieur(s) à 200€ : " + inf200);
    System.out.println("Montant total des chèques < 200€ : " + totalInf200 +"€");
    System.out.println("Chèque(s) supérieur(s) ou = à 200€ : " + egalSup200);
    System.out.println("Montant total des chèques >= 200€ : " + totalEgalSup200 +"€");
    System.out.println("#Chèques plus petit : " + numeroPlusPetit);
    System.out.println("Plus petit montant : " + plusPetit +"€");
    System.out.println("#Chèques plus grand : " + numeroPlusGrand);
    System.out.println("Plus grand montant : " + plusGrand +"€");
    
}

}

Answer 1

I think you misunderstanding here.

double input = scan.nextDouble();

This line will only scan the console ONCE for the input, meaning you will only get two result from your program:

• You enter 0 and the program prints all logs then exit.
• You enter a double differs 0 and the program keep running forever since the input value is not updated inside the loop.