enum Color { RED, GREEN, BLUE; } public class Main { public static void main(String[] args) { Color color = Color.RED; switch (color) { case RED: System.out.println("红色"); break; case GREEN: System.out.println("绿色"); break; case BLUE: System.out.println("蓝色"); break; } } }
enum Operation { ADD { @Override public int apply(int a, int b) { return a + b; } }, SUBTRACT { @Override public int apply(int a, int b) { return a - b; } }; public abstract int apply(int a, int b); } public class Main { public static void main(String[] args) { System.out.println(Operation.ADD.apply(1, 2)); // 输出 3 System.out.println(Operation.SUBTRACT.apply(1, 2)); // 输出 -1 } }
enum City { NEW_YORK, LOS_ANGELES, CHICAGO; } public class Main { public static void main(String[] args) { Map<City, String> cityNames = new HashMap<>(); cityNames.put(City.NEW_YORK, "New York"); cityNames.put(City.LOS_ANGELES, "Los Angeles"); cityNames.put(City.CHICAGO, "Chicago"); System.out.println(cityNames.get(City.NEW_YORK)); // 输出 New York } }
enum Day { MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY; } public class Main { public static void main(String[] args) { List<Day> daysOfWeek = Arrays.asList(Day.values()); System.out.println(daysOfWeek); // 输出 [MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY] } }
通过使用枚举类型,您可以简化逻辑,提高代码的可读性和可维护性。