# 003public class Switch-case結構式 { switch (n) {case 1:敘述1;break; case 2:敘述2;break; default:敘述4;} 亂數月份/當月天數判斷 ``` public static void main(String[] args) { int Month = (int)(Math.random()*12 + 1); // 1 - 12 System.out.println(Month); switch (Month){ case 1: case 3: case 5: case 7: case 8: case 10: case 12: System.out.println("31"); break; case 4: case 6: case 9: case 11: System.out.println("30"); break; case 2: System.out.println("28"); break; default:(其他) System.out.println("OK"); } } } ```