The valueOf Method of Enum Class in Java

In Java, Enum is a special data type that enables a variable to be a set of predefined constants.

Common examples include days of the week, directions, colors, etc. As Enums are constants, they are all defined in uppercase letters.

the valueOf Method of Enum Class in Java

In Java, we use the enum keyword to define an Enum type to create our data type classes.

Enum class has the valueOf() method, which returns the enum constant of the specified enum type with the specified name. The name of the enum type must match the identifier used to declare the enum constant.

The valueOf() method is case-sensitive, and it will throw an IlegalArgumentException with an invalid string.

Here we have used Colors enum. An Enum class automatically gets a static valueOf method at the compile time.

The color variable of the type Colors is the enum type defined in this program given below. The color variable can take one of the color enum constants (RED, GREEN, BLUE, WHITE, PINK, YELLOW). In our case, color is set to Colors.BLUE.

Using the valueOf(), we have an instance of Enum class Colors for a given string value. The colorRed variable will point to the Colors.RED. We can see that in the print statement below in output.

public class EnumTest {
  enum Colors { RED, GREEN, BLUE, WHITE, PINK, YELLOW }

  public static void main(String[] arg) {
    Colors color = Colors.BLUE;
    Colors colorRed = Colors.valueOf("RED");
    System.out.println("color : " + color);
    System.out.println("Colors.valueOf(RED) : " + colorRed);
  }
}

Output:

color : BLUE
Colors.valueOf(RED) : RED