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
}
}