我将如何使用while循环来不断请求用户输入

Question

我用while循环尝试了几件事，但似乎无法使其正常工作。 我想一直请求用户输入，直到用户输入数字0，这是我到目前为止的代码：

import java.util.*;

public class Task10 {

    public static void main(String[] args) {
        System.out.println("Enter a year to check if it is a leap year");
        Scanner input = new Scanner(System.in);
        int year = input.nextInt();

        if ((year % 4 == 0) || ((year % 400 == 0) && (year % 100 != 0)))
            System.out.println(year + " is a leap year");
        else
            System.out.println(year + " is not a leap year");
    }
}

Answer 1

在输入行上方使用while循环作为：

 while(true)

并且，使用if条件break 。

if(year == 0)
    break;

另外， leap year条件在您的代码中是错误的。 它应该是：

if((year % 100 == 0 && year % 400 == 0) || (year % 4 == 0 && year % 100 != 0))
    //its a leap year
else
    //its not

PS：在评论中，我将提供完整的代码：

import java.util.*;

public class Task10 {

public static void main(String[] args) {
    System.out.println("Enter a year to check if it is a leap year");
    while(true){
    Scanner input = new Scanner(System.in);
        int year = input.nextInt();
        if(year == 0)
            break;
        if((year % 100 == 0 && year % 400 == 0) || (year % 4 == 0 && year % 100 != 0))
            System.out.println(year + " is a leap year");
        else
            System.out.println(year + " is not a leap year");
    }
}

}

Answer 2

您应该将输入代码放入一个while循环和执行while循环中，直到year等于或小于0。

public static void main(String[] args) {
        int year = 1;
        while(year > 0)
        {
            System.out.println("Enter a year to check if it is a leap year");
            Scanner input = new Scanner(System.in);
            year = input.nextInt();
            if ((year % 4 == 0) || ((year % 400 == 0) && (year % 100 != 0)))
                System.out.println(year + " is a leap year");
            else
                System.out.println(year + " is not a leap year");
        }


    }

Answer 3

您需要做一些事情来保持输入循环运行，直到遇到停止条件为止（在您的情况下，这是用户输入0 ）

// First get the scanner object with the input stream
Scanner sc = new Scanner(System.in); 

// Just using do-while here for no reason, you can use a simple while(true) as well
do{
    int input = sc.nextInt();  // read the next input
    if (int == 0) { // check if we need to exit out
        // break only if 0 is entered, this means we don't want to run the loop anymore
        break;
    } else {
        // otherwise, do something with the input
    }
} while(true); // and keep repeating