Java枚举的本质及其方法

Java枚举

所有的枚举类型都是Enum 类的子类

import java.util.Scanner;

public class EnumTest {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.println("Enter a size: (SMALL, MEDIUM, LARGE, EXTRA_LARGE)");
        String input = in.next().toUpperCase();
        //toString的逆方法是静态方法valueOf
        Size size = Enum.valueOf(Size.class, input);
        System.out.println("size="+size);
        System.out.println("abbreviation=" + size.getAbbreviation());
        //ordinal方法返冋enum声明中枚举常量的位置
        if (size.ordinal() == 3) System.out.println("you get the EXTRA_LARGE");
        //除此，每个枚举类型都有一个静态的values方法，它将返回一个包含全部枚举值的数组
    }
}

enum Size{
    SMALL("S"),MEDIUM("M"),LARGE("L"),EXTRA_LARGE("XL");

    private Size(String abbreviation){ this.abbreviation = abbreviation; }

    public String getAbbreviation(){ return abbreviation; }

    private String abbreviation;
}