java枚舉類型如何遍歷

在Java中，可以使用以下方法遍歷枚舉類型：

1. 使用for-each循環遍歷枚舉類型的所有值：

public enum Weekday {
    MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY;
}

public class EnumTraversal {
    public static void main(String[] args) {
        for (Weekday day : Weekday.values()) {
            System.out.println(day);
        }
    }
}

2. 使用EnumSet和Iterator遍歷枚舉類型的所有值：

import java.util.EnumSet;
import java.util.Iterator;

public enum Weekday {
    MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY;
}

public class EnumTraversal {
    public static void main(String[] args) {
        EnumSet<Weekday> weekdays = EnumSet.allOf(Weekday.class);
        Iterator<Weekday> iterator = weekdays.iterator();

        while (iterator.hasNext()) {
            Weekday day = iterator.next();
            System.out.println(day);
        }
    }
}

3. 使用Java 8的Stream API遍歷枚舉類型的所有值：

import java.util.stream.Stream;

public enum Weekday {
    MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY;
}

public class EnumTraversal {
    public static void main(String[] args) {
        Stream<Weekday> weekdays = Weekday.stream();

        weekdays.forEach(System.out::println);
    }
}

以上三種方法都可以遍歷枚舉類型的所有值。你可以根據自己的需求和編程風格選擇合適的方法。