/* 编写程序:从键盘上输入2019年的“month”和“day”,要求通过程序输出 输入的日期为2019年的第几天。(使用switch-case) */ import java.util.Scanner; class SwitchCaseTest2{ public static void main(String[] args){ Scanner scan = new Scanner(System.in); System.out.println("请输入2019年的month:"); int month = scan.nextInt(); System.out.println("请输入2019年的day:"); int day = scan.nextInt(); //方法一:冗余 //定义一个变量来保存总天数 /*int sumDays = 0; if(month == 1){ sumDays = day; }else if(month = 2){ sumDays = 31 + day; }else if(month == 3){ sumDays = 31 + 28 + day; }else if(month == 4){ sumDays = 31 + 28 + 31 + day; …… else{//month == 12 //sumDays = …… +day; }*/ //方法二:冗余 /*switch(month){ case 1: sumDays = day; break; case 2: sumDays = 31 + day; break; …… }*/ //方法三: int sumDays = 0; switch(month){ case 12: sumDays += 30; case 11: sumDays += 31; case 10: sumDays += 30; case 9: sumDays += 31; case 8: sumDays += 31; case 7: sumDays += 30; case 6: sumDays += 31; case 5: sumDays += 30; case 4: sumDays += 31; case 3: sumDays += 28; case 2: sumDays += 31; case 1: sumDays += day; } System.out.println("2019年"+month+"月"+day+"日是当年的第"+sumDays+"天"); } }