zj-Exercise/java-Eclipse/day04/SwitchCaseTest2.java

/*
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");
		
	}
}