String To Enum Inwards Coffee - Conversion Example

Creating Enum from String
You tin practise Enum from String past times using Enum.valueOf() method. valueOf() is a static method which is added on every Enum degree during compile fourth dimension together with it's implicitly available to all Enum along alongside values(), name() together with cardinal() methods. In venture to practise Enum from String, String must live on same equally declared Enum otherwise, the code volition throw "java.lang.IllegalArgumentException: No enum const class". the same technique tin live on used to convert String into Enum instance equally well. This is the minute business office of Enum conversion tutorial, inwards the get-go part, nosotros accept seen how to convert Enum to String inwards Java. If you lot accept non read that yet, depository fiscal establishment check it out. Also from Java vii onwards, Java started supporting String constants inwards switch cases, merely you lot should ever prefer Enum over both Integer together with String constant because Enum provides type safety. The compiler volition ensure that wrong value is non supplied, merely inwards the instance of String together with Integer, the compiler volition depository fiscal establishment check whether a variable is of the right type, merely it won't depository fiscal establishment check values, which is why you lot should role Enum to define a well-known fixed give away of things. 

Enum to String Conversion Example 

Here is a code illustration of String to Enum conversion inwards Java. It demonstrates both the technique which nosotros accept discussed thus far to practise Enum from String inwards Java. You tin role the same technique to convert whatever String to the corresponding Enum equally well. Always brand certain to overstep right String in venture to avoid IllegalArgumentExcpeiton in Java.



There are few to a greater extent than or less other method of converting String to Enum also which compares passed String to all Enum instances declared past times iterating over all Enum instances using values() method together with and thus comparison them using equals(). Though that method industrial plant good it requires to a greater extent than code than unproblematic Enum.valueOf().

Problem: We accept a declared Enum Currency, which contains Enum instances USD INR EURO, Now We accept a String "USD" together with nosotros desire to convert that String into Enum, it should convert into Currency.USD

Solution: Currency.valueOf("USD") or Enum.valueOf(Currency.class, "USD")

package example;

/**
 * Java plan for creating Enum instance from String inwards Java.
 * This plan demonstrate how to role Enum.valueOf() method to convert enum instance
 * into String. beware that String must live on same equally declared Enum instances together with they are
 * instance sensitive equally well. "UsD" instead of "USD" volition throw IllegalArgumentException
 *
 * @author Javin Paul
 */
public class StringToEnum {
    private enum Currency {USD, AUD, GBP, EURO }  
   
    public static void main(String args[]) {
       
        //Converting String to Enum inwards Java
        String usd = "USD";
       
        //Enum to String using Enum.valueOf()
        Enum currency = Enum.valueOf(Currency.class, usd);
       
        //Enum to String using Currency.valueOf()
        currency = Currency.valueOf(usd);
       
        System.out.println("String to Enum Example : " + currency);
     
        //This Enum to String conversion volition throw Exception
        String INR = "INR";
        //java.lang.IllegalArgumentException: No enum const degree
        Currency rupee = Currency.valueOf("INR");
    }
}
Output:
String to Enum Example : USD
Exception inwards thread "main" java.lang.IllegalArgumentException: No enum const class test.CollectionTest$Currency.INR
        at java.lang.Enum.valueOf(Enum.java:196)
        at test.CollectionTest$Currency.valueOf(CollectionTest.java:16)
        at test.CollectionTest.main(CollectionTest.java:32)
Java Result: 1 

That’s all on How to practise Enum from String inwards Java. This is a real frequent requirement  and Java programmers should live on familiar alongside this technique to convert String to Enum easily. In Summary prefer Enum over String to acquire compile fourth dimension checking together with type security merely since String is a global type together with you lot may shop your information inwards the database inwards the cast of String together with runtime each of those String converted to Enum.


Further Learning
Complete Java Masterclass
see tip)

How to role valueOf method of Enum (check here)

String to Enum inwards Java alongside Example (check here)

Top xv Java Enum Interview Questions alongside Answers (see here)

Difference betwixt RegularEnumSet together with JumboEnumSet inwards Java (read here)

Learn how to role Enum inwards Java alongside a Simple Example (check here)

Can nosotros role Enum inwards Switch Statement inwards Java (Yes)

How to loop over Enum constants inwards Java (example)

What Every Java Programmer Should know close Enum (click here)

10 points close Enum inwards Java (see here)

Can Enum accept Constructor inwards Java (learn here)