JAVA swich语句

swich判断年份月份LocalDate

import java.time.LocalDate;
import java.util.Scanner;

public class Swich {
    public static void main(String[] args) {
        int y = 2022;
        int m = 2;
        int days = switch (m) {
            case 2 -> {
                yield LocalDate.of(y, m, 1).isLeapYear() ? 29 : 28;
            }
            case 4, 6, 9, 11 -> 30;
            default -> 31;
        };
        System.out.printf("%d年%d月有%d天", y, m, days);
    }
}

低端写法

        int y = 2021;
        int m = 4;

        int days = switch (m) {
            case 2 -> y % 400 == 0 || y % 4 == 0 && y % 100 != 0 ? 29 : 28;
            case 4, 6, 9, 11 -> 30;
            default -> 31;
        };
        System.out.printf("%d年%d月有%d天", y, m, days);