Question

早上好，我正在尝试自己学习一些东西。因为我已经超负荷工作了。这只是我正在从事的一个小型练习程序。我明白了这一点，但是我不确定发生了什么。如果输入的数字不是2，则会显示“请输入有效的数字，谢谢” 当给定2时，它说“数字甚至没有，所以还有余数” 我不确定为什么要得到这个。为什么不接受其他数字，为什么说2不是偶数？对于我所解释的错误的任何帮助，将不胜感激。谢谢。

import java.util.Scanner;

public class Assignment1
{

    //Scanner keyboard = new Scanner(System.in);
    //int num = keyboard.nextInt();

    public static int isEven()
    {
        Scanner keyboard = new Scanner(System.in);
        int num = keyboard.nextInt();

        switch (num)
        {

          case 1:
              if (num % 2 == 0)
              System.out.println("The Number is Even no Remainders");
              break;
          case 2:
              if (num % 2 != 0);
              System.out.println("The Number is not even so there are Remainders");
              break;
          default:
             System.out.println("Please input a valid number, Thank you.");

        }//switch
        /*pull number from user
        //store in num
        //if even print message num is even
        //else print message not an even number
         * This is the remainder of my psuedcode notes to remind me how my
         * mind was flowing
         */
        return num;

    } //isEven

    public static void main (String args[])
    {
        Assignment1.isEven();

    }//main
}//public class assignment one

Answer 1

开关盒的文档为here。

现在尝试一下，我在行中添加了一些注释。 仔细阅读。

public class Assignment1 {

    public static int isEven() {
        Scanner keyboard = new Scanner(System.in);
        int num = keyboard.nextInt();

        num = num % 2; // divide by 2 and get a remainder.
        switch (num) {
            case 0: //case 0 means if number equal to zero
                System.out.println("The Number is Even no Remainders");
                break;
            case 1: // case 1 means if number equal to one
                System.out.println("The Number is not even so there are Remainders");
                break;
            default: // if no one match if not a valid.
                System.out.println("Please input a valid number, Thank you.");

        }//switch
        /*pull number from user
        //store in num
        //if even print message num is even
        //else print message not an even number
         * This is the remainder of my psuedcode notes to remind me how my
         * mind was flowing
         */
        return num;

    } //isEven

    public static void main(String args[]) {
        Assignment1.isEven();

    }//
}

仅接受数字2并给出错误的奇数或偶数输出

1 个答案: