The enum type in D language is used to define named constants which can be referred to by a collective name.
The keyword enum is used to declare an enumeration list as a type of enum.
enum nameOf_enum {
enumeration list
}
enum keyword indicates that the set of data is of type enum.nameOf_enum parameter in the syntax is the identifier for the enumeration list. When an enumeration list is declared without the nameOf_enum being provided, the enum is automatically given a type of int.We can access the members of an enumeration list by writing the name of the enum followed by a dot and then the name of the member of interest. The index can be returned using a formatter print and the formatted set to an integer. See the example below:
import std.stdio;enum Users { students, teachers, admins, executives};int main() {Users personnel;personnel= Users.students;writefln("Frequent Users: %s", personnel);writefln("Executives index: %d", Users.executives);return 0;}
The 0 in the output of the code above is the index and value of tall in the height enum relative to the size or length of the enum. We can also see how the member tall is referenced in the formatted printing method writefln in line 6.
Let’s look at the code below:
import std.stdio;enum Users { students, teachers, admins, executives};int main() {Users personnel;personnel= Users.students;writefln("Frequent Users: %s", personnel);writefln("Executives index: %d", Users.executives);return 0;}
enum Usersand give some members.main(), which returns a value.personnel is declared as a data type of the enum Users.student from the Users enum.Note: Enumeration lists have a default value of their position index value, they can also be assigned values like below:
enum alphas{x =4,y = 6,z = 12}