enum用法(Java中enum的用法有哪些)

簡介

枚舉是Java1.5引入的新特性,通過關鍵字enum來定義枚舉類。枚舉類是一種特殊類,它和普通類一樣可以使用構造器、定義成員變量和方法,也能實現一個或多個接口,但枚舉類不能繼承其他類.

一,常量定義

publicenumWeekDay{SUN,MON,TUE,WED,THT,FRI,SAT}

二,swich

publicenumWeekDay{SUN,MON,TUE,WED,THT,FRI,SAT}publicclassSelectDay{WeekDayweekday=WeekDay.SUN;publicvoidselect(){switch(weekday){caseSUN:weekday=WeekDay.SUN;break;...}}}

三,向枚舉添加新方法

publicenumColor{RED("紅色",1),GREEN("綠色",2),BLANK("白色",3),YELLO("黃色",4);//成員變量privateStringname;privateintindex;//構造方法privateColor(Stringname,intindex){this.name=name;this.index=index;}//普通方法publicstaticStringgetName(intindex){for(Colorc:Color.values()){if(c.getIndex()==index){returnc.name;}}returnnull;}//getset方法publicStringgetName(){returnname;}publicvoidsetName(Stringname){this.name=name;}publicintgetIndex(){returnindex;}publicvoidsetIndex(intindex){this.index=index;}}

四,覆蓋枚舉方法

publicenumColor{RED("紅色",1),GREEN("綠色",2),BLANK("白色",3),YELLO("黃色",4);//成員變量privateStringname;privateintindex;//構造方法privateColor(Stringname,intindex){this.name=name;this.index=index;}//覆蓋方法@OverridepublicStringtoString(){returnthis.index+"_"+this.name;}}

五,實現接口

publicinterfaceBehaviour{voidprint();StringgetInfo();}publicenumColorimplementsBehaviour{RED("紅色",1),GREEN("綠色",2),BLANK("白色",3),YELLO("黃色",4);//成員變量privateStringname;privateintindex;//構造方法privateColor(Stringname,intindex){this.name=name;this.index=index;}//接口方法@OverridepublicStringgetInfo(){returnthis.name;}//接口方法@Overridepublicvoidprint(){System.out.println(this.index+":"+this.name);}}

六,接口組織枚舉

publicinterfaceFood{enumCoffeeimplementsFood{BLACK_COFFEE,DECAF_COFFEE,LATTE,CAPPUCCINO}enumDessertimplementsFood{FRUIT,CAKE,GELATO}}

七,枚舉集合

publicclassTest{publicstaticvoidmain(String[]args){EnumSet<WeekDay>week=EnumSet.noneOf(WeekDay.class);week.add(WeekDay.MON);System.out.println("EnumSet中的元素:"+week);week.remove(WeekDay.MON);System.out.println("EnumSet中的元素:"+week);week.addAll(EnumSet.complementOf(week));System.out.println("EnumSet中的元素:"+week);week.removeAll(EnumSet.range(WeekDay.FRI,WeekDay.SAT));System.out.println("EnumSet中的元素:"+week);}

看完上述內容,你們對Java中enum的用法有哪些有進一步的了解嗎?如果還想了解更多知識或者相關內容,請關注本站行業資訊頻道,感謝大家的支持。