JAVA最容易忽视的数据类型之枚举详解

enum Color
{
    RED, GREEN, BLUE;
}
 
public class Test
{
    // 执行输出结果
    public static void main(String[] args)
    {
        Color c1 = Color.RED;
        System.out.println(c1);
    }
}

Color myColor = Color.Red;
if (myColor == Color.Green)
{
    // ...
}

public class Outer {
    private int x;

    public void doSomething() {
        Inner inner = new Inner();
        inner.doSomethingElse();
    }

    private class Inner {
        private void doSomethingElse() {
            Status status = Status.IN_PROGRESS;
            // ...
        }

        private enum Status {
            IN_PROGRESS,
            COMPLETED,
            FAILED
        }
    }
}

List<String> strings = new ArrayList<>();
strings.add("foo");
strings.add("bar");
strings.add("baz");

Iterator<String> iterator = strings.iterator();
while (iterator.hasNext()) {
    String str = iterator.next();
    System.out.println(str);
}

public class Main {
    enum Day {
        MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY
    }

    public static void main(String[] args) {
        Day day = Day.TUESDAY;

        switch (day) {
            case MONDAY:
                System.out.println("Today is Monday");
                break;
            case TUESDAY:
                System.out.println("Today is Tuesday");
                break;
            case WEDNESDAY:
                System.out.println("Today is Wednesday");
                break;
            case THURSDAY:
                System.out.println("Today is Thursday");
                break;
            case FRIDAY:
                System.out.println("Today is Friday");
                break;
            case SATURDAY:
                System.out.println("Today is Saturday");
                break;
            case SUNDAY:
                System.out.println("Today is Sunday");
                break;
            default:
                System.out.println("Invalid day");
                break;
        }
    }
}