Question

我正在尝试从在线Java教程中完成一项作业，我目前正在讨论有关While循环的问题。这是我的代码：

import java.util.Scanner;

public class bird {
    public static void main(String[] args){
        Scanner bucky = new Scanner(System.in);
        final String end = "END";
        String bird;
        int amount;

        System.out.println("What bird did you see in your garden? ");
        bird = bucky.nextLine();

        while(!(bird.equals(end))){
            System.out.println("How many were in your garden? ");
            amount = bucky.nextInt();

        }
    }
}

我的问题是，如果用户输入END，则代码意味着终止，因此它需要在While循环之外。但如果不在循环内部，它就不会为更多类型的鸟类重复这个问题。有没有办法让第一个＆＃34;你看到了什么鸟？＆＃34;如果满足结束条件，循环内部还有条件退出循环？

Answer 1

一种方法（参见代码注释）：

public static void main(String[] args){
    Scanner bucky = new Scanner(System.in);
    final String end = "END";
    String bird;
    int amount;

    while(true){ // loop "forever"
        System.out.println("What bird did you see in your garden? ");
        bird = bucky.nextLine();
        if (end.equals(bird)) { // break out if END is entered
            break;
        }

        System.out.println("How many were in your garden? ");
        amount = bucky.nextInt();
        bucky.nextLine(); // consume the newline character after the number

        System.out.println("we saw " + amount + " of " + bird); // for debugging
    }
}

Answer 2

试试这个快速解决方案：

import java.util.Scanner;

public class Bird {
    public static void main(String[] args){

        Scanner bucky = new Scanner(System.in);
        System.out.println("What bird did you see in your garden? ");

        while(!(bucky.nextLine().equalsIgnoreCase("END"))){
            System.out.println("How many were in your garden? ");
            bucky.nextInt();
            System.out.println("What bird did you see in your garden? ");
            bucky.nextLine();
        }
    }
}

而在Java中循环具有结束条件

2 个答案: