Java - Enum String

Java enum is a special construct to represents a group of pre-defined constant strings and provides clarity in code while used as constants in application code. By default, an enum string representation is the same as its declaration. Consider the following example:

enum WEEKDAY { MONDAY, TUESDAY, WEDNESDAY, THRUSDAY, FRIDAY, SATURDAY, SUNDAY }

If we print the string representation of the above enum using the enum directly, using toString(), or using the name() method, it will print the same string as declared.

System.out.println(WEEKDAY.MONDAY);
System.out.println(WEEKDAY.MONDAY.toString());
System.out.println(WEEKDAY.MONDAY.name());

It will print the result as shown below:

MONDAY
MONDAY
MONDAY

Overriding Enum toString() Method

Now in case, we want to change the default string representation to the enum's string representation, we can create an overridden toString() method for each value of the enum constructor as shown below:

enum WEEKDAY {
	MONDAY{
      // overridden toString() method per value
      public String toString() {
        return "Day 1 of the Week: Monday";
      }
	};
	
	// or override toString() per enum
	// priority will be given to value level toString() method.
    public String toString() {
       return "Day 1 of the Week: Monday";
    }	
}

In this case, we're overriding a default toString() method of the enum to give a custom description.

Example: Overriding toString() Method in Java

In this example, we've created an enum WEEKDAY. Using toString() method, we're setting a custom description of enum value.

package com.tutorialspoint;

enum WEEKDAY { 
   // enum value constants
   MONDAY, TUESDAY, WEDNESDAY, THRUSDAY, FRIDAY, SATURDAY, SUNDAY;

   // override the toString() method for custom description
   @Override
   public String toString() {
      return switch(this) {
         case MONDAY: yield "Day 1";
         case TUESDAY:yield "Day 2";
         case WEDNESDAY:yield "Day 3";
         case THRUSDAY:yield "Day 4";
         case FRIDAY:yield "Day 5";
         case SATURDAY:yield "DAY 6";
         case SUNDAY: yield "Day 7";
      };
   }	
}
public class Tester {
   public static void main(String[] args) {
      // invoke toString() internally
      System.out.println(WEEKDAY.MONDAY);
      // invoke toString explicitly	  
      System.out.println(WEEKDAY.TUESDAY.toString());
      // invoke name() method to get the default name
      System.out.println(WEEKDAY.WEDNESDAY.name());
   }
}

Output

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

Day 1
Day 2
WEDNESDAY

Example: Overriding toString() Method Per Value in Java

In this example, we've overridden toString() methods per value of this enum WEEKDAY. This way we can customize string representation per value in this way as well.

package com.tutorialspoint;

enum WEEKDAY {
   
   // override the toString() method for custom description
   MONDAY{
      @Override
      public String toString() {
         return "Day 1";
      }
   },
   TUESDAY{
      @Override
      public String toString() {
         return "Day 2";
      }		
   },
   WEDNESDAY{
      @Override
      public String toString() {
         return "Day 3";
      }
   },
   THRUSDAY{
      @Override
      public String toString() {
         return "Day 4";
      }
   },
   FRIDAY{
      @Override
      public String toString() {
         return "Day 5";
      }
   },
   SATURDAY{
      @Override
      public String toString() {
         return "Day 6";
      }
   },
   SUNDAY{
      @Override
      public String toString() {
         return "Day 7";
      }
   };	
}
public class Tester {
   public static void main(String[] args) {
      // invoke toString() internally
      System.out.println(WEEKDAY.MONDAY);
      // invoke toString explicitly	  
      System.out.println(WEEKDAY.TUESDAY.toString());
      // invoke name() method to get the default name
      System.out.println(WEEKDAY.WEDNESDAY.name());
   }
}

Output

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

Day 1
Day 2
WEDNESDAY

enum name() method is final and cannot be overridden. It can be used to get the default name of the enum while string representation of enum is overridden by toString() method.