The semicolon ( ) at the end of the enum constants are optional. The enum can be defined within or outside the class because it is similar to a class. String enums allow you to give a meaningful and readable value when your code runs, independent of the name of the enum member itself. The ordinal() method returns the index of the enum value. The Java compiler internally adds the ordinal() method when it creates an enum. What is the purpose of the ordinal() method in the enum? The valueOf() method returns the value of given constant enum. The Java compiler internally adds the valueOf() method when it creates an enum. What is the purpose of the valueOf() method in the enum? The values() method returns an array containing all the values of the enum. The Java compiler internally adds the values() method when it creates an enum. What is the purpose of the values() method in the enum? It internally creates a static and final class for the enum. Note: Java compiler internally adds values(), valueOf() and ordinal() methods within the enum at compile time. Enum may implement many interfaces but cannot extend any class because it internally extends Enum class.Enum can have fields, constructors and methods.We can have fields, constructors, methods, and main methods in Java enum. Enum fields are treated like fields on any other type. Java Enum internally inherits the Enum class, so it cannot inherit any other class, but it can implement many interfaces. Enums can store additional information affiliated with each value in fields. Here, we can define an enum either inside the class or outside the class. Unlike C/C++, enum in Java is more powerful. The enum data type (also known as Enumerated Data Type) is used to define an enum in Java. It is available since JDK 1.5.Įnums are used to create our own data type like classes. The Java enum constants are static and final implicitly. Java Enums can be thought of as classes which have a fixed set of constants (a variable that does not change). Its external to the enum, so you can instantiate as many configurations as you need. An EnumMap sounds more like what you need. Enums are singletons, so effectively you can only have one configuration active at any given time. So, we have enum constants in capital letters. Using an enum to hold configurable values like this looks like an entirely wrong design. According to the Java naming conventions, we should have all constants in capital letters. It can be used for days of the week (SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, and SATURDAY), directions (NORTH, SOUTH, EAST, and WEST), season (SPRING, SUMMER, WINTER, and AUTUMN or FALL), colors (RED, YELLOW, BLUE, GREEN, WHITE, and BLACK) etc. The Enum in Java is a data type which contains a fixed set of constants.
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