java 枚举enum

枚举类

一个类中的对象 认为个数是有限且固定的 可以将每一个对象一一列举出来；

JDK1.5版本之后可以直接定义enum类型；

　　我们自己定义的enum类直接默认继承Enum(java.lang包）

　　我们自己定义的enum类型不能再写extends 但是可以实现；

package eenum;
/*
public enum Day{
	//描述了七个当前类的对象
	monday("星期一",1),tuesday("星期二",1),wednesday,thursday,friday,saturday,sunday
	private String name;
	private int index
	private Day(){
	}
	private Day(String name,int index){
		this.name=name;
		this.index=index;
	}
	public String getName(){
		return this.name;
	}
	public void setName(String name){
		this.name=name;
	}
}
*/

public enum Day{
	//描述了七个当前类的对象
	monday,tuesday,wednesday,thursday,friday,saturday,sunday
}


/*
public enum Day{
	//描述了七个当前类的对象
	monday,tuesday,wednesday,thursday,friday,saturday,sunday
}
*/

/*
public class Day{//7个对象
	private Day(){
	}//构造方法私有
	//所有对象都是属性
	public static final Day monday=new Day();
	public static final Day tuesday=new Day();
	public static final Day wednesday=new Day();
	public static final Day thursday=new Day();
	public static final Day friday=new Day();
	public static final Day saturday=new Day();
	public static final Day sunday=new Day();
	
	
}
*/

　　

package eenum;
import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input=new Scanner(System.in);
		System.out.println("请输入一个星期的英文单词");
		String dd=input.nextLine();
		Day day=Day.valueOf(dd);
		switch(day){
			case monday:
				System.out.println("星期一");
				break;
			case tuesday:
				System.out.println("星期二");
				break;
			case wednesday:
				System.out.println("星期三");
				break;
			case thursday:
				System.out.println("星期四");
				break;
			case friday:
				System.out.println("星期五");
				break;
			case saturday:
				System.out.println("星期六");
				break;
			case sunday:
				System.out.println("星期日");
				break;
			default:
				System.out.println("错误");
				
		}
	}
}

/*
public class Test{
	public static void main(String[] args){
		Day a=Day.monday;
		Day[] ds=Day.values();
		for(Day d:ds){
			System.out.println(d.name()+"--"+d.ordinal());
		}
		System.out.println();
		Day d=Day.valueOf("monday");
		System.out.println(d.name()+"=="+d.ordinal());
	}
}
*/
/*
public class Test{
	public static void main(String[] args){
		Day day=Day.monday;
		
	}
}
*/