What is the example of enum?

An enum type is a special data type that enables for a variable to be a set of predefined constants. The variable must be equal to one of the values that have been predefined for it. Common examples include compass directions (values of NORTH, SOUTH, EAST, and WEST) and the days of the week.

Can enum be used in HashMap?

In HashMap, we can use Enum as well as any other object as a key. It doesn’t allow storing null key. It allows to store the null keys as well values, but there should be only one null key object and there can be any number of null values. HashMap internally uses the HashTable.

Can we use enum in Map?

In HashMap, there is no constraint. You can use Enum as well as any other Object as key. 2. Performance : EnumMap is a specialized Map implementation for use with enum type keys.

How do you write an enum?

Example of applying Enum on a switch statement

  1. class EnumExample5{
  2. enum Day{ SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY}
  3. public static void main(String args[]){
  4. Day day=Day.MONDAY;
  5. switch(day){
  6. case SUNDAY:
  7. System.out.println(“sunday”);
  8. break;

What is enum in C with example?

Enumeration or Enum in C is a special kind of data type defined by the user. It consists of constant integrals or integers that are given names by a user. The use of enum in C to name the integer values makes the entire program easy to learn, understand, and maintain by the same or even different programmer.

Why do we use enums in Java?

Enums are used when we know all possible values at compile-time, such as choices on a menu, rounding modes, command-line flags, etc. It is not necessary that the set of constants in an enum type stay fixed for all time. In Java (from 1.5), enums are represented using enum data type.

What is EnumMap and EnumSet?

EnumMap is a specialized implementation of the Map interface for the enumeration types. EnumSet is a specialized implementation of the Set interface for the enumeration types. EnumMap is internally represented as an array. EnumSet is internally represented as a BitVector.

Is enum better than HashMap?

In short, EnumMap is best suited for enum keys, for which it has optimized and performed better than HashMap in Java.

What is enum in C# with example?

In C#, an enum (or enumeration type) is used to assign constant names to a group of numeric integer values. It makes constant values more readable, for example, WeekDays. Monday is more readable then number 0 when referring to the day in a week.

What is enum answer?

Enum is a java keyword and very useful in our everyday programming. We use Enum for a variable to be set of a predefined constant value. Before Java 1.5 we used public static final keywords to represent constants.