Java Class getEnumConstants() Method

---

---

Description

The Java Class getEnumConstants() method returns the elements of this enum class or null if this Class object does not represent an enum type.

Declaration

Following is the declaration for java.lang.Class.getEnumConstants() method

public T[] getEnumConstants()

Parameters

NA

Return Value

This method returns an array containing the values comprising the enum class represented by this Class object in the order they're declared, or null if this Class object does not represent an enum type.

Exception

NA

Getting Enum Constants of the Underlying Class Example

The following example shows the usage of java.lang.Class.getEnumConstants() method. In this program, we've created a Class ClassDemo and an enum Programming. In main method, we've retrieved class of Programming enum and then using getEnumConstants() method, enum values are retrieved and printed.

package com.tutorialspoint;

enum Programming {
   java,
   python,
}

public class ClassDemo {

   public static void main(String[] args) {
      Class cls = Programming.class;

      // returns the elements of this enum class
      for(Object obj: cls.getEnumConstants()) {
         System.out.println(obj);
      }
   }
} 

Output

Let us compile and run the above program, this will produce the following result −

java
python

Getting Enum Constants of the Thread Example

The following example shows the usage of java.lang.Class.getEnumConstants() method. In this program, we've created a Class ClassDemo. In main method, we've retrieved class of State enum of Thread and then using getEnumConstants() method, enum values are retrieved and printed.

package com.tutorialspoint;

public class ClassDemo {

   public static void main(String[] args) {
      Class cls = Thread.State.class;

      // returns the elements of this enum class
      for(Object obj: cls.getEnumConstants()) {
         System.out.println(obj);
      }
   }
} 

Output

Let us compile and run the above program, this will produce the following result −

NEW
RUNNABLE
BLOCKED
WAITING
TIMED_WAITING
TERMINATED

Getting Enum Constants as Null Example

The following example shows the usage of java.lang.Class.getEnumConstants() method. In this program, we've created a Class ClassDemo. In main method, we've retrieved class of ClassDemo and then using getEnumConstants() method, enum values are retrieved and a corresponding message is printed.

package com.tutorialspoint;

public class ClassDemo {

   public static void main(String[] args) {
      Class cls;
      try {
         cls = Class.forName("com.tutorialspoint.ClassDemo");
         Object[] enums = cls.getEnumConstants();

         if(enums != null) {
            System.out.println("Enums are present.");
         }else {
            System.out.println("Enums are not available.");
         }

      } catch (ClassNotFoundException e) {
         e.printStackTrace();
      }
   }
}  

Output

Let us compile and run the above program, this will produce the following result −

Enums are not available.