Java-使用用户输入退出do-while循环

Question

我正在尝试编写一个程序，允许在无限循环中生成随机数。如果用户按下'c'，它将脱离循环。但是循环只在我按下c时开始，它应该在之前开始，当我按下'c'时它应该停止。

import java.util.Random;
import java.util.Scanner;

public class main{

    public static void main (String[] args) {

        Random rand = new Random();

        int[] randNumber = new int[100];

        Scanner scanner = new Scanner(System.in);
        char c = scanner.next().charAt(0);

        do {
            for (int i = 0; i <= 99; i++) {
                randNumber[i] = rand.nextInt(100);
            }

            for (int i = 0; i < 99; i++) {
                if (randNumber[i] < randNumber[i + 1]) {
                    System.out.println("Number " + randNumber[i] + " smaller than " + randNumber[i + 1]);
                } else if (randNumber[i] > randNumber[i + 1]) {
                    System.out.println("Number " + randNumber[i] + " greater than " + randNumber[i + 1]);
                } else if (randNumber[i] == randNumber[i + 1]) {
                    System.out.println("Number " + randNumber[i] + " equal to " + randNumber[i + 1]);
                } else {
                    System.out.println("Wrong!");
                }
            }
        } while (c == 'c');
    }
}

另外，我想知道如何才能只使用while循环而不是do-while循环来完成这个程序。当我使用while时，我从while(1)开始，然后使用来自input的if语句中断循环，但这也不起作用。内部仍然有两个for循环。

多谢

Answer 1

您需要询问循环内部的用户输入；否则，c永远不会更改。

        Random rand = new Random();

        int[] randNumber = new int[100];

        Scanner scanner = new Scanner(System.in);
        
        // Just set it to 'c' as default so it enters the loop at least once. IMO this is better than an infinite loop with breakout or having another default value for c and checking it, or using a do while loop
        char c = 'c';

        while (c == 'c') {
            for (int i = 0; i <= 99; i++) {
                randNumber[i] = rand.nextInt(100);
            }

            for (int i = 0; i < 99; i++) {
                if (randNumber[i] < randNumber[i + 1]) {
                    System.out.println("Number " + randNumber[i] + " smaller than " + randNumber[i + 1]);
                } else if (randNumber[i] > randNumber[i + 1]) {
                    System.out.println("Number " + randNumber[i] + " greater than " + randNumber[i + 1]);
                } else if (randNumber[i] == randNumber[i + 1]) {
                    System.out.println("Number " + randNumber[i] + " equal to " + randNumber[i + 1]);
                } else {
                    System.out.println("Wrong!");
                }
            }

            // Ask for the next input
            char c = scanner.next().charAt(0);
        }

Answer 2

关于first query,在do-while循环中移动您接受输入的代码行,以这种方式在每次迭代之后,它将请求输入,如果您输入'c',它将继续,否则它将被释放。关于第二个查询，如果您使用while（1）并使用if语句检查用户是否输入了'c'，如果用户输入了'c'，则可以使用。