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 Hugh* 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");}}}

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

package com.liaojianya.chapter1;
/*** This program demonstrates thw way of implements * display the number of days according to 12 months.* @author Hugh* 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");}}}

随机产生一个月份并显示月份: 3
March has 31 days

package com.liaojianya.chapter1;
/*** This program demonstrates the way of using array to storage days of each month.* @author Hugh* 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!");            }}}

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!