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Best way to create enum of strings?

Posted by: admin November 2, 2017 Leave a comment

Questions:

What is the best way to have a enum type represent a set of strings?

I tried this:

enum Strings{
   STRING_ONE("ONE"), STRING_TWO("TWO")
}

How can I then use them as Strings?

Answers:

I don’t know what you want to do, but this is how I actually translated your example code….

/**
 * 
 */
package test;

/**
 * @author The Elite Gentleman
 *
 */
public enum Strings {
    STRING_ONE("ONE"),
    STRING_TWO("TWO")
    ;

    private final String text;

    /**
     * @param text
     */
    private Strings(final String text) {
        this.text = text;
    }

    /* (non-Javadoc)
     * @see java.lang.Enum#toString()
     */
    @Override
    public String toString() {
        return text;
    }
}

Alternatively, you can create a getter method for text.

You can now do Strings.STRING_ONE.toString();

Questions:
Answers:

Custom String Values for Enum

from http://javahowto.blogspot.com/2006/10/custom-string-values-for-enum.html

The default string value for java enum is its face value, or the element name. However, you can customize the string value by overriding toString() method. For example,

public enum MyType {
  ONE {
      public String toString() {
          return "this is one";
      }
  },

  TWO {
      public String toString() {
          return "this is two";
      }
  }
}

Running the following test code will produce this:

public class EnumTest {
  public static void main(String[] args) {
      System.out.println(MyType.ONE);
      System.out.println(MyType.TWO);
  }
}


this is one
this is two

Questions:
Answers:

Use its name() method:

public class Main {
    public static void main(String[] args) throws Exception {
        System.out.println(Strings.ONE.name());
    }
}

enum Strings {
    ONE, TWO, THREE
}

yields ONE.

Questions:
Answers:

Depending on what you mean by “use them as Strings”, you might not want to use an enum here. In most cases, the solution proposed by The Elite Gentleman will allow you to use them through their toString-methods, e.g. in System.out.println(STRING_ONE) or String s = "Hello "+STRING_TWO, but when you really need Strings (e.g. STRING_ONE.toLowerCase()), you might prefer defining them as constants:

public interface Strings{
  public static final String STRING_ONE = "ONE";
  public static final String STRING_TWO = "TWO";      
}

Questions:
Answers:

Either set the enum name to be the same as the string you want or, more generally,you can associate arbitrary attributes with your enum values:

enum Strings {
   STRING_ONE("ONE"), STRING_TWO("TWO");
   private final String stringValue;
   Strings(final String s) { stringValue = s; }
   public String toString() { return stringValue; }
   // further methods, attributes, etc.
}

It’s important to have the constants at the top, and the methods/attributes at the bottom.

Questions:
Answers:

If you do not want to use constructors, and you want to have a special name for the method, try it this:

public enum MyType {
  ONE {
      public String getDescription() {
          return "this is one";
      }
  },    
  TWO {
      public String getDescription() {
          return "this is two";
      }
  };

  public abstract String getDescription();
}

I suspect that this is the quickest solution. There is no need to use variables final.