Enum类的方法如下图所示

我们来看一下几个常用的方法：

values()方法：返回枚举类型的对象数组。该方法可以很方便地遍历所有的枚举值。

valueOf(String str)：可以把一个字符串转为对应的枚举类对象。要求字符 串必须是枚举类对象的“名字”。如不是，会有运行时异常：IllegalArgumentException。

toString()：返回当前枚举类对象常量的名称

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 举例说明：

values()方法：返回枚举类型的对象数组。该方法可以很方便地遍历所有的枚举值。

public class SeasonTest01 {public static void main(String[] args) {Season1 summer = Season1.SUMMER;//toString():System.out.println(summer);//System.out.println(Season1.class.getSuperclass());System.out.println("===================================");//values():Season1[] values = Season1.values();for (int i = 0; i < values.length; i++) {System.out.println(values[i]);}}
}
//使用enum关键词枚举类
enum Season1{//1.提供当前枚举类的多个对象,多个对象之间用“,“隔开，末尾对象";"结束SPRING ("春天","春暖花开"),SUMMER ("夏天","夏日炎炎"),AUTUMN ("秋天","秋高气爽"),WINTER ("冬天","冰天雪地");//2.声明Season对象的属性:private final修饰private final String seasonName;private final String seasonDesc;//3.私有化类的构造器,并给对象属性赋值private Season1(String seasonName,String seasonDesc){this.seasonName = seasonName;this.seasonDesc = seasonDesc;}//4.其他诉求1：获取枚举类对象的属性public String getSeasonName() {return seasonName;}public String getSeasonDesc() {return seasonDesc;}//4.其他诉求1：提供toString()
//    @Override
//    public String toString() {
//        return "Season1{" +
//                "seasonName='" + seasonName + '\'' +
//                ", seasonDesc='" + seasonDesc + '\'' +
//                '}';
//    }
}

运行结果如下：

我们再以线程的状态为例：

public class SeasonTest01 {public static void main(String[] args) {Season1 summer = Season1.SUMMER;//toString():System.out.println(summer);//System.out.println(Season1.class.getSuperclass());System.out.println("===================================");//values():Season1[] values = Season1.values();for (int i = 0; i < values.length; i++) {System.out.println(values[i]);}System.out.println("===============================");Thread.State[] values1 = Thread.State.values();for (int i = 0; i < values1.length; i++) {System.out.println(values1[i]);}}
}
//使用enum关键词枚举类
enum Season1{//1.提供当前枚举类的多个对象,多个对象之间用“,“隔开，末尾对象";"结束SPRING ("春天","春暖花开"),SUMMER ("夏天","夏日炎炎"),AUTUMN ("秋天","秋高气爽"),WINTER ("冬天","冰天雪地");//2.声明Season对象的属性:private final修饰private final String seasonName;private final String seasonDesc;//3.私有化类的构造器,并给对象属性赋值private Season1(String seasonName,String seasonDesc){this.seasonName = seasonName;this.seasonDesc = seasonDesc;}//4.其他诉求1：获取枚举类对象的属性public String getSeasonName() {return seasonName;}public String getSeasonDesc() {return seasonDesc;}//4.其他诉求1：提供toString()
//    @Override
//    public String toString() {
//        return "Season1{" +
//                "seasonName='" + seasonName + '\'' +
//                ", seasonDesc='" + seasonDesc + '\'' +
//                '}';
//    }
}

运行结果如下图：

 valueOf(String str)：可以把一个字符串转为对应的枚举类对象。要求字符 串必须是枚举类对象的“名字”。如不是，会有运行时异常：IllegalArgumentException。

public class SeasonTest01 {public static void main(String[] args) {Season1 summer = Season1.SUMMER;//toString():System.out.println(summer);//System.out.println(Season1.class.getSuperclass());System.out.println("===================================");//values():Season1[] values = Season1.values();for (int i = 0; i < values.length; i++) {System.out.println(values[i]);}System.out.println("===============================");Thread.State[] values1 = Thread.State.values();for (int i = 0; i < values1.length; i++) {System.out.println(values1[i]);}System.out.println("=======================================");//valuesOf(String objName):返回枚举类中对象名是objName的对象Season1 winter = Season1.valueOf("WINTER");System.out.println(winter);}
}
//使用enum关键词枚举类
enum Season1{//1.提供当前枚举类的多个对象,多个对象之间用“,“隔开，末尾对象";"结束SPRING ("春天","春暖花开"),SUMMER ("夏天","夏日炎炎"),AUTUMN ("秋天","秋高气爽"),WINTER ("冬天","冰天雪地");//2.声明Season对象的属性:private final修饰private final String seasonName;private final String seasonDesc;//3.私有化类的构造器,并给对象属性赋值private Season1(String seasonName,String seasonDesc){this.seasonName = seasonName;this.seasonDesc = seasonDesc;}//4.其他诉求1：获取枚举类对象的属性public String getSeasonName() {return seasonName;}public String getSeasonDesc() {return seasonDesc;}//4.其他诉求1：提供toString()
//    @Override
//    public String toString() {
//        return "Season1{" +
//                "seasonName='" + seasonName + '\'' +
//                ", seasonDesc='" + seasonDesc + '\'' +
//                '}';
//    }
}

运行结果如下：

 假如我们将括号里的WINTER写错了写成了WINTER1.那就找不到了。运行结果如下：

 我们可以发现如果没有objName的枚举类对象，则抛异常：IllegalArgumentException

 感谢观看！！!