使用switch case语句来显示月份的对应天数

方法一：控制台输入月份

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package com.liaojianya.chapter1;   import java.util.Scanner;   /**  * This program demonstrates thw way of implements  * display the number of days according to 12 months.  * @author LIAO JIANYA  * 2016年7月19日  */ public class MonthAndDays {     public static void main(String[] args)     {         System.out.println("please enter a number : 1~12");         @SuppressWarnings("resource")         Scanner scan = new Scanner(System.in);         int month = scan.nextInt();         switch (month)         {         case 1:             System.out.println("January has 31 days");             break;         case 2:             System.out.println("February has 28 days");             break;         case 3:             System.out.println("March has 31 days");             break;         case 4:             System.out.println("April has 30 days");             break;         case 5:             System.out.println("May has 31 days");             break;         case 6:             System.out.println("June has 30 days");             break;         case 7:             System.out.println("July has 31 days");             break;         case 8:             System.out.println("August has 31 days");             break;         case 9:             System.out.println("September has 30 days");             break;         case 10:             System.out.println("Octor has 31 days");             break;         case 11:             System.out.println("November has 30 days");             break;         case 12:             System.out.println("December has 31 days");             break;             default:                 System.out.println("Error month information");         }     }   }

　　运行结果：

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please enter a number : 1~12 4 April has 30 days

　　方法二：随机产生1-12之间的某个整数：

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package com.liaojianya.chapter1; /**  * This program demonstrates thw way of implements  * display the number of days according to 12 months.  * @author LIAO JIANYA  * 2016年7月19日  */ public class MonthAndDays {     public static void main(String[] args)     {         int month = (int)(Math.random() * 12);         System.out.println("随机产生一个月份并显示月份: " + month);         switch (month)         {         case 1:             System.out.println("January has 31 days");             break;         case 2:             System.out.println("February has 28 days");             break;         case 3:             System.out.println("March has 31 days");             break;         case 4:             System.out.println("April has 30 days");             break;         case 5:             System.out.println("May has 31 days");             break;         case 6:             System.out.println("June has 30 days");             break;         case 7:             System.out.println("July has 31 days");             break;         case 8:             System.out.println("August has 31 days");             break;         case 9:             System.out.println("September has 30 days");             break;         case 10:             System.out.println("Octor has 31 days");             break;         case 11:             System.out.println("November has 30 days");             break;         case 12:             System.out.println("December has 31 days");             break; //          default: //              System.out.println("Error month information");         }     }   }

　　运行结果：

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1 2	随机产生一个月份并显示月份: 3 March has 31 days

　　分析：随机产生月份时，default可以省略。

显示12个月各自全部的天数：

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package com.liaojianya.chapter1; /**  * This program demonstrates the way of using array to storage days of each month.  * @author LIAO JIANYA  * 2016年7月19日  */ public class ArrayDemo {     public static void main(String[] args)     {         int[] month = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};         for(int i = 0; i < month.length; i++)         {             System.out.println("第" + (i+1) + "月有" + month[i] + "天!");                   }     }   }

　　运行结果：

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第1月有31天! 第2月有28天! 第3月有31天! 第4月有30天! 第5月有31天! 第6月有30天! 第7月有31天! 第8月有31天! 第9月有30天! 第10月有31天! 第11月有30天! 第12月有31天!