Enumeration | Data Types

Introduction to Enumeration

Enumeration, also known as enum, is a user-defined data type in C. It is mainly used to assign names to integral constants, making the code more readable and maintainable. The enum keyword is used to define enumerated types.

Syntax of Enumeration

enum enum_name {
    constant1,
    constant2,
    ...,
    constantN
};

Here, enum_name is the name of the enumeration (optional), and constant1, constant2, ..., constantN are the names of the constants. By default, the value of the first constant is 0, the second is 1, and so on.

Example of Enumeration

Below is a simple example demonstrating the use of enumeration in C:

#include <stdio.h>

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

int main() {
    enum Day today;
    today = WEDNESDAY;

    printf("Day %d", today);
    return 0;
}

In this example, the Day enumeration is defined with seven constants representing the days of the week. The variable today is of enum type Day, and it is assigned the value WEDNESDAY. The output will be:

Day 3

Assigning Values to Enumeration Constants

You can also assign specific values to the enumeration constants. For example:

enum Day {
    SUNDAY = 1,
    MONDAY,
    TUESDAY = 10,
    WEDNESDAY,
    THURSDAY,
    FRIDAY,
    SATURDAY
};

In this case, SUNDAY is assigned the value 1, MONDAY is 2 (previous value + 1), TUESDAY is 10, WEDNESDAY is 11, and so on.

Using Enumeration in Switch Case

Enumerations are often used in switch-case statements for better code readability. Here is an example:

#include <stdio.h>

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

int main() {
    enum Day today;
    today = FRIDAY;

    switch (today) {
        case SUNDAY:
            printf("Today is Sunday");
            break;
        case MONDAY:
            printf("Today is Monday");
            break;
        case TUESDAY:
            printf("Today is Tuesday");
            break;
        case WEDNESDAY:
            printf("Today is Wednesday");
            break;
        case THURSDAY:
            printf("Today is Thursday");
            break;
        case FRIDAY:
            printf("Today is Friday");
            break;
        case SATURDAY:
            printf("Today is Saturday");
            break;
        default:
            printf("Invalid day");
    }

    return 0;
}

In this example, the value of today is FRIDAY, and the switch-case statement prints "Today is Friday".

Benefits of Enumeration

Readability: Enums make the code more readable by allowing the use of meaningful names instead of numbers.
Maintainability: It is easier to maintain and update the code as changes in enum values are centralized.
Type Safety: Enums provide type safety by ensuring that only valid values are assigned to variables.

Conclusion

Enumeration is a powerful feature in C that enhances code readability, maintainability, and type safety. By using enums, you can assign meaningful names to constants, making your code easier to understand and manage. This tutorial covered the basics of enumeration, including its syntax, examples, and benefits.

Enumeration in C Language