java --枚舉

枚舉用來存放一些只存在幾種狀況的對象，例如：星期、顏色等。
若枚舉只有一個成員，則能夠做爲一種單例模式的實現方式。
#1.自定義枚舉類

//自定義枚舉類  
class Season{
	
	//2.定義兩個屬性
	private final String seasonName;
	private final String seasonDesc;
	
	//1.私有構造器，防止外部調用
	private Season(String seasonName,String seasonDesc){
		this.seasonName = seasonName;
		this.seasonDesc = seasonDesc;
	}
	
	//3.建立枚舉類的對象
	public static final Season SPRING = new Season("春天", "春暖花開");
	public static final Season SUMMER = new Season("夏天", "夏日炎炎");
	public static final Season AUTUMN = new Season("秋天", "秋高氣爽");
	public static final Season WINTER = new Season("冬天", "千里冰封 ");
	
	public String getSeasonName() {
		return seasonName;
	}

	public String getSeasonDesc() {
		return seasonDesc;
	}

	@Override
	public String toString() {
		return "Season [seasonName=" + seasonName + ", seasonDesc=" + seasonDesc + "]";
	}
}

自定義枚舉類的使用

public class TestSeason {
	public static void main(String[] args) {
		Season spring = Season.SPRING;
		System.out.println(spring);
		System.out.println(spring.getSeasonName());
	}
}

#2.enum

//使用enum枚舉類  
enum Season{
	
	//1.列舉出全部的類型
	SPRING("春天", "春暖花開"),
	SUMMER("夏天", "夏日炎炎"),
	AUTUMN("秋天", "秋高氣爽"),
	WINTER("冬天", "千里冰封 ");
	
	//2.定義兩個屬性
	private final String seasonName;
	private final String seasonDesc;
	
	//3.私有構造器，防止外部調用
	private Season(String seasonName,String seasonDesc){
		this.seasonName = seasonName;
		this.seasonDesc = seasonDesc;
	}
	public String getSeasonName() {
		return seasonName;
	}
	public String getSeasonDesc() {
		return seasonDesc;
	}
	@Override
	public String toString() {
		return "Season [seasonName=" + seasonName + ", seasonDesc=" + seasonDesc + "]";
	}
}

使用方法

public static void main(String[] args) {
		
		//1.返回枚舉類全部的對象
		Season[] season = Season.values();
		for (int i = 0; i < season.length; i++) {
			System.out.println(season[i]);
		}
		//2.單獨使用一種狀況
		String tmp = Season.SPRING.getSeasonName();
		System.out.println(tmp);
	}