本篇文章给大家介绍一下Java中enum常见的用法。有一定的参考价值,有需要的朋友可以参考一下,希望对大家有所帮助。
常量定义
public enum WeekDay { SUN, MON, TUE, WED, THT, FRI, SAT }
swich
public enum WeekDay { SUN, MON, TUE, WED, THT, FRI, SAT } public class SelectDay{ WeekDay weekday = WeekDay.SUN; public void select(){ switch(weekday){ case SUN: weekday = WeekDay.SUN; break; ... } } }
向枚举添加新方法
public enum Color { RED("红色", 1), GREEN("绿色", 2), BLANK("白色", 3), YELLO("黄色", 4); // 成员变量 private String name; private int index; // 构造方法 private Color(String name, int index) { this.name = name; this.index = index; } // 普通方法 public static String getName(int index) { for (Color c : Color.values()) { if (c.getIndex() == index) { return c.name; } } return null; } // get set 方法 public String getName() { return name; } public void setName(String name) { this.name = name; } public int getIndex() { return index; } public void setIndex(int index) { this.index = index; } }
覆盖枚举方法
public enum Color { RED("红色", 1), GREEN("绿色", 2), BLANK("白色", 3), YELLO("黄色", 4); // 成员变量 private String name; private int index; // 构造方法 private Color(String name, int index) { this.name = name; this.index = index; } //覆盖方法 @Override public String toString() { return this.index+"_"+this.name; } }
实现接口
public interface Behaviour { void print(); String getInfo(); } public enum Color implements Behaviour{ RED("红色", 1), GREEN("绿色", 2), BLANK("白色", 3), YELLO("黄色", 4); // 成员变量 private String name; private int index; // 构造方法 private Color(String name, int index) { this.name = name; this.index = index; } //接口方法 @Override public String getInfo() { return this.name; } //接口方法 @Override public void print() { System.out.println(this.index+":"+this.name); } }
接口组织枚举
public interface Food { enum Coffee implements Food{ BLACK_COFFEE,DECAF_COFFEE,LATTE,CAPPUCCINO } enum Dessert implements Food{ FRUIT, CAKE, GELATO } }
枚举集合
public class Test { public static void main(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); }
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