Enumeration Fundamentals : enum « Data Type « Java Tutorial






  1. Java Tutorial
  2. Data Type
  3. enum

An enumeration is created using the new enum keyword.

enum Week {
  Monday, Tuesday, Wednesday, Thursday, Friday, Saturaday, Sunday
}
  1. The identifiers Monday, Tuesday, and so on, are called enumeration constants.
  2. Each is implicitly declared as a public, static member of Week.
  3. Their type is the type of the enumeration in which they are declared.
  4. These constants are called self-typed.

You declare and use an enumeration variable in much the same way as the primitive types.

Week aWeekDay;

Because aWeekDay is of type Week, the only values that it can be assigned (or contain) are those defined by the enumeration.

enum Week {
  Monday, Tuesday, Wednesday, Thursday, Friday, Saturaday, Sunday
}

public class MainClass {
  public static void main(String args[]) {
    Week aWeekDay;

    aWeekDay = Week.Monday;

    // Output an enum value.
    System.out.println("Value of aWeekDay: " + aWeekDay);
    System.out.println();
  }
}

Value of aWeekDay: Monday




2.43.enum
2.43.1.Enumeration Fundamentals
2.43.2.How to define an enumeration
2.43.3.Enums in a Class
2.43.4.equals and = operator for enum data type
2.43.5.Comparing Enumeration Values
2.43.6.Two enumeration constants can be compared for equality by using the == relational operator
2.43.7.uses an enum, rather than interface variables, to represent the answers.
2.43.8.enum type with its own method
2.43.9.Enum type field
2.43.10.enum with switch