Java Language Tutorial => Get enum constant by name

Example

Say we have an enum DayOfWeek:

enum DayOfWeek {
    SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY;
}

An enum is compiled with a built-in static valueOf() method which can be used to lookup a constant by its name:

String dayName = DayOfWeek.SUNDAY.name();
assert dayName.equals("SUNDAY");

DayOfWeek day = DayOfWeek.valueOf(dayName);
assert day == DayOfWeek.SUNDAY;

This is also possible using a dynamic enum type:

Class<DayOfWeek> enumType = DayOfWeek.class;
DayOfWeek day = Enum.valueOf(enumType, "SUNDAY");
assert day == DayOfWeek.SUNDAY;

Both of these valueOf() methods will throw an IllegalArgumentException if the specified enum does not have a constant with a matching name.

The Guava library provides a helper method Enums.getIfPresent() that returns a Guava Optional to eliminate explicit exception handling:

DayOfWeek defaultDay = DayOfWeek.SUNDAY;
DayOfWeek day = Enums.valueOf(DayOfWeek.class, "INVALID").or(defaultDay);
assert day == DayOfWeek.SUNDAY;

PDF - Download Java Language for free

Previous Next

Java Language

Fastest Entity Framework Extensions

Example

Got any Java Language Question?

Java Language

Java Language Enums Get enum constant by name

Fastest Entity Framework Extensions

Example

Got any Java Language Question?