用Java实现切换后输出不打印

Question

我正在使用enum/switch case和Zeller的公式来表示一年中的哪一天，一个特定的日期将是哪一天。在我实现代码的枚举/开关部分的前几天，我的代码正在打印（如下所示）。在我放入enum/switch大小写之后，当我在DrJava中运行它时，它确实会提示日期、月份和年份，但是一旦它通过switch大小写，就不会打印任何内容

 import java.util.*;

public class Zeller {

  public enum DaysOftheWeek {

    SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY;
  }

  private static int value;



  public Zeller (int value){
    this.value = value;
  }
  public int getValue(){
    return this.value;
  }

    public static void main(String[] args) {
      DetermineDay(value);        // Create a Scanner
        Scanner input = new Scanner(System.in);

        // Prompt the user to enter a year, month and a day


        System.out.print("Enter month: 1-12: ");
        int month = input.nextInt();

        System.out.print("Enter the day of the month: 1-31: ");
        int day = input.nextInt();

        System.out.print("Enter year (e.g., 2008): ");
        int year = input.nextInt();

        // Check if the month is January or February
        // If the month is January and February, convert to 13, and 14,
        // and year has to -1. (Go to previous year).
        if (month == 1 || month == 2) {
            month += 12;
            year--;
        }

        // Compute the answer
        int k = year % 100; // The year of the century
        int j = (int)(year / 100.0); // the century
        int q = day;
        int m = month;
      int h = (q + (int)((13 * (m + 1)) / 5.0) + k + (int)(k / 4.0)

           + (int)(j / 4.0) + (5 * j)) % 7;
      value = h;

      System.out.println(value);

    }

    public static String DetermineDay(int value){

        String result = "Day of the week is "; 

    switch (value){

      case 1 :
        System.out.println(result + "Sunday");
        break;
      case 2 :
        System.out.println(result + "Monday"); 
        break;
      case 3:
      System.out.println(result + "Tuesday");
      break;
      case 4:
        System.out.println(result + "Wednesday");

        break;
      case 5:
        System.out.println(result + "Thursday"); 
        break;

      case 6:
        System.out.println(result + "Friday"); 
        break;
      case 7 :
        System.out.println( result + "Saturday");
        break;
      default : 
        System.out.println ("Looks like that day doesn't exist");
        break;
    }


   return result;     
  }
}

Answer 1

>

如果要使用DetermineDay输出日期，则需要在完成计算并将结果赋值后的末尾调用该方法。

这似乎有效，但在您的算法中有一个问题。当使用日期4/11/2016尝试这个程序时，它确实发现这是一个星期五，但当使用日期5/5/2016时，即今天，输出是-看起来那天不存在-所以是的。

在deterneDay结束时，您不需要返回结果，因为您已经在开关中sop了结果。

import java.util.*;

public class Zeller {
 public enum DaysOftheWeek {
  SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY;
 }

 private static int value;

 public Zeller (int value){
  this.value = value;
 }

 public int getValue(){
  return this.value;
 }

 public static void main(String[] args) {
  // Create a Scanner
  Scanner input = new Scanner(System.in);

  // Prompt the user to enter a year, month and a day
  System.out.print("Enter month: 1-12: ");
  int month = input.nextInt();

  System.out.print("Enter the day of the month: 1-31: ");
  int day = input.nextInt();

  System.out.print("Enter year (e.g., 2008): ");
  int year = input.nextInt();

  // Check if the month is January or February
  // If the month is January and February, convert to 13, and 14,
  // and year has to -1. (Go to previous year).
  if (month == 1 || month == 2) {
    month += 12;
    year--;
  }

  // Compute the answer
  int k = year % 100; // The year of the century
  int j = (int)(year / 100.0); // the century
  int q = day;
  int m = month;
  int h = (q + (int)((13 * (m + 1)) / 5.0) + k + (int)(k / 4.0) + (int)(j / 4.0) + (5 * j)) % 7;
  value = h;

  System.out.println(value);
  DetermineDay(value);
 }

 public static void DetermineDay(int value){
  String result = "Day of the week is "; 

  switch (value){
   case 1 :
    System.out.println(result + "Sunday");
    break;

    case 2 :
     System.out.println(result + "Monday"); 
     break;

    case 3:
     System.out.println(result + "Tuesday");
     break;

    case 4:
     System.out.println(result + "Wednesday");
     break;

    case 5:
     System.out.println(result + "Thursday"); 
     break;

    case 6:
     System.out.println(result + "Friday"); 
     break;

    case 7 :
     System.out.println( result + "Saturday");
     break;

    default : 
     System.out.println ("Looks like that day doesn't exist");
     break;
  }
 }
}