java_enum

enum是java5之后定义的枚举类型

1.定义一个enum

public enum Size{        //以下是3个Size类型实例        SMALL("S"),MIDDLE("m"),LARGE("l");                private Size(String abbreviation){            this.abbreviation = abbreviation;        }                private String abbreviation;        public String getAbbreviation() {            return abbreviation;        }            }

2.测试enum 相关方法

public class TestEnum {    public static void main(String[] args) {          System.out.println(Size.SMALL.toString()); //返回SMALL          System.out.println(Size.SMALL.ordinal()); //返回SMALL实例下标,从0开始          Size s = (Size)Enum.valueOf(Size.class, "SMALL"); //返回实例名字为SMALL的 Size实例          System.out.println(s.getAbbreviation());  //获取实例的abbreviation属性          Size[] sizes = Size.values();  //遍历Size对象          System.out.println(Size.SMALL.compareTo(Size.MIDDLE)); //枚举常量SMLL出现在MIDDLE之前,返回-1,相同返回0,否则返回正值    }}