Java - Convert String type value into enum type tutorial

The Java enum class has a built-in method named valueOf() that allows you to convert a String into its equivalent enum value.

The valueOf() method of the enum class is a static method, so you can call it directly from the class without creating an instance.

Let’s see an example of converting a String into an enum.

Suppose you have a ColorsEnum declared in your Java code as follows:

enum ColorsEnum {
    RED, GREEN, BLUE;
}

You can convert any String value that matches one of the three ColorsEnum values above.

For example, the string "RED" will be converted to ColorsEnum.RED like this:

ColorsEnum color = ColorsEnum.valueOf("RED");
System.out.println(color); // RED
System.out.println(color == ColorsEnum.RED); // true

Please note that the valueOf() method accepts only a String type value and is case-sensitive.

When the string doesn’t match the case of any enum values, Java will throw the IllegalArgumentException error:

ColorsEnum color = ColorsEnum.valueOf("red");
// ERROR: No enum constant Main.ColorsEnum.red

ColorsEnum color = ColorsEnum.valueOf("WHITE");
// ERROR: No enum constant Main.ColorsEnum.WHITE

Here’s the complete Java code for converting a String into an enum value:

class Main {
    // Create the enum class
    enum ColorsEnum {
        RED, GREEN, BLUE;
    }

    public static void main(String[] myArgs) {
        // Convert the string into an enum
        ColorsEnum color = ColorsEnum.valueOf("RED");
        System.out.println(color); // RED
        System.out.println(color == ColorsEnum.RED); // true
    }
}

Now you’ve learned how to convert a String into an enum in Java.

Feel free to use the code above in your Java project. 😉