java.lang.reflect.Field的isEnumConstant()方法,用于检查此字段是否表示枚举类型的元素。如果此字段表示枚举类型的元素,则方法返回true,否则返回false。
用法:
public boolean isEnumConstant()
参数:此方法接受不接受任何内容。
返回:仅当此字段表示枚举类型的元素时,此方法才返回true。
以下示例程序旨在说明isEnumConstant()方法:
示例1:
// Java program to illustrate
// isEnumConstant () method
import java.lang.reflect.Field;
import java.time.Month;
public class GFG {
public static void main(String[] args)
throws NoSuchFieldException
{
// get all declared fields of Month class
Field[] declaredFields
= Month.class.getDeclaredFields();
// loop through Field array
// and print Field name and
// check whether the field is EnumConstant
for (int i = 0; i < declaredFields.length; i++) {
System.out.print(
"Field --> Name: "
+ declaredFields[i].getName()
+ "; isEnumConstant: "
+ declaredFields[i]
.isEnumConstant()
+ "\n");
}
}
}
输出:
Field --> Name: JANUARY; isEnumConstant: true Field --> Name: FEBRUARY; isEnumConstant: true Field --> Name: MARCH; isEnumConstant: true Field --> Name: APRIL; isEnumConstant: true Field --> Name: MAY; isEnumConstant: true Field --> Name: JUNE; isEnumConstant: true Field --> Name: JULY; isEnumConstant: true Field --> Name: AUGUST; isEnumConstant: true Field --> Name: SEPTEMBER; isEnumConstant: true Field --> Name: OCTOBER; isEnumConstant: true Field --> Name: NOVEMBER; isEnumConstant: true Field --> Name: DECEMBER; isEnumConstant: true Field --> Name: ENUMS; isEnumConstant: false Field --> Name: $VALUES; isEnumConstant: false
示例2:
// Java program to illustrate
// isEnumConstant () method
import java.lang.reflect.Field;
public class GFG {
public static void main(String[] args)
throws NoSuchFieldException
{
// get all declared fields of Symbols class
Field[] declaredFields
= Symbols.class.getDeclaredFields();
// loop through Field array
// and print Field name and
// check whether the field is EnumConstant
for (int i = 0; i < declaredFields.length; i++) {
System.out.print(
"Field --> Name: "
+ declaredFields[i].getName()
+ "; isEnumConstant: "
+ declaredFields[i]
.isEnumConstant()
+ "\n");
}
}
private static enum Symbols {
Alpha,
Beta,
Gamma
}
}
输出:
Field --> Name: Alpha; isEnumConstant: true Field --> Name: Beta; isEnumConstant: true Field --> Name: Gamma; isEnumConstant: true Field --> Name: ENUM$VALUES; isEnumConstant: false
参考文献: https://docs.oracle.com/javase/8/docs/api/java/lang/reflect/Field.html#isEnumConstant–
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注:本文由纯净天空筛选整理自AmanSingh2210大神的英文原创作品 Field isEnumConstant() method in Java with Examples。非经特殊声明,原始代码版权归原作者所有,本译文未经允许或授权,请勿转载或复制。