今天我們來簡單的使用一下java裏面的枚舉類型enum,使用簡單的東南西北來確定
enum Direction
{
EAST, SOUTH, WEST, NORTH
}
class EnumDemo
{
public static void main(String[] args)
{
Direction dir = Direction.NORTH;
switch(dir)
{
case EAST:
System.out.println("向東");
break;
case SOUTH:
System.out.println("向南");
break;
case WEST:
System.out.println("向西");
break;
case NORTH:
System.out.println("向北");
break;
}
}
}
這是一個簡單的例子,下面我們將探尋枚舉類型的對應關係,首先需要知道一個知識:
*java.lang.Enum.ordinal() 方法返回枚舉常量的序數(它在枚舉聲明,其中初始常量分配的零序位)。
enum Direction
{
EAST("東",1), SOUTH("南",2),
WEST("西",3), NORTH("北",4);
private Direction(String desc, int num){
this.desc=desc; this.num=num;
}
private String desc;
private int num;
public String getDesc(){ return desc; }
public int getNum(){ return num; }
}
class EnumDemo2
{
public static void main(String[] args)
{
Direction dir = Direction.NORTH;
for( Direction d : Direction.values())
System.out.println(
d.getDesc() + "," +d.getNum()
+ "," + d.ordinal() );
}
}
運行結果如上圖