• C Program to Representing Days of the Week Using Enumeration

    Welcome to our blog post on using enumeration in C programming to represent days of the week! In this post, we will explore how enumeration can be a useful tool for organizing and manipulating data in C programs. Whether you’re new to programming or looking to expand your knowledge, this post will provide valuable insights and tips for working with enumerations in C. So let’s dive in!

    Introduction to Enumeration

    Enumeration, also known as enum, is a user-defined data type in C that allows us to define a set of named constants. This data type makes it easier to work with predefined values, as it assigns meaningful names to a set of related values. In the context of representing days of the week, enumeration can be particularly useful as it provides a clear and intuitive way to represent each day.

    In C, enumeration is declared using the enum keyword, followed by a list of constant values enclosed in curly braces. Assign a unique integer value, starting from 0 by default, to each constant value. However, we can assign custom integer values to the constants if desired.

    Now let’s see how we can use enumeration to represent days of the week in C.

    Using Enumeration for Days of the Week

    To represent days of the week using enumeration in C, we can declare an enum with seven constants, each representing a day. Here’s an example:

    enum DaysOfWeek {

    In this example, we have defined an enumeration named DaysOfWeek with seven constants representing the days of the week. By default, the first constant Sunday is assigned the value 0, Monday is assigned the value 1, and so on.

    Now that we have defined our enumeration, let’s explore how we can use it in our C programs.

    Accessing Enumeration Constants

    To access the enumeration constants, we can simply refer to them by their names. For example, to print the value of Tuesday, we can use the following code:

    printf("Tuesday: %d\n", Tuesday);

    This will output:

    Tuesday: 2

    Similarly, we can use the enumeration constants in expressions and comparisons. For instance, to check if today is Friday, we can write the following code:

    if (today == Friday) {
      printf("It's Friday! Time to celebrate!\n");

    Here, today is assumed to be a variable representing the current day. If the value of today matches the constant Friday, the corresponding message will be printed.

    Customizing Enumeration Constants

    The default assignment for enumeration constants assigns consecutive integer values starting from 0. However, we can assign custom values to the constants if necessary. We can achieve this by explicitly specifying the integer values for each constant.

    Let’s say we want to assign Monday as the first day of the week instead of Sunday. We can modify our enum declaration as follows:

    enum DaysOfWeek {
      Monday = 1,

    In this example, we have assigned the value 1 to Monday explicitly. The subsequent constants (Tuesday, Wednesday, etc.) will be assigned consecutive integer values, starting from the value assigned to the previous constant.

    By customizing the values of enumeration constants, we can adapt the representation of days of the week to different requirements or conventions.

    Iterating through Enumeration Constants

    We can also use enumeration constants in loops, enabling us to iterate through the days of the week. To do this, we need to define a variable of the enumeration type and initialize it with the first constant. We can then increment this variable until we reach the last constant.

    Here’s an example that demonstrates how to iterate through the days of the week using an enumeration:

    enum DaysOfWeek day = Sunday;
    while (day <= Saturday) {
      printf("Today is %d\n", day);
      day++; // Increment the value of 'day'

    In this example, we start with the day variable initialized to Sunday. The loop continues until the value of day is less than or equal to Saturday. Within the loop, we print the current value of day and then increment it using the ++ operator.

    This will output:

    Today is 0
    Today is 1
    Today is 2
    Today is 3
    Today is 4
    Today is 5
    Today is 6

    Handling Invalid Enumeration Values

    In some cases, the value of a variable representing the day of the week may be invalid, such as when the value is supplied by user input or obtained from external sources. To handle such situations, we can use conditional statements to check if the value falls within the valid range of the enumeration constants.

    Here’s an example that demonstrates how to handle invalid enumeration values:

    enum DaysOfWeek day;
    // Assume 'input' is obtained from user input
    int input = 8;
    if (input >= Sunday && input <= Saturday) {
      day = input;
      printf("Valid day: %d\n", day);
    } else {
      printf("Invalid day value\n");

    In this example, we check if the value of input falls within the range of the enumeration constants. If it does, we assign the value to the day variable and proceed with further operations. Otherwise, we handle the case of an invalid day value.


    In this blog post, we explored how C programming can use enumeration to represent days of the week. We learned how to declare an enumeration and assign custom values to its constants. We also saw how to access the enumeration constants, iterate through them, and handle invalid enumeration values.

    By using enumeration, we can make our C programs more readable, maintainable, and intuitive, especially when working with a fixed set of related values. Whether we are developing a calendar application, scheduling system, or any other program that requires handling days of the week, enumeration provides us with a powerful tool to organize and manipulate our data effectively.

    If you want to delve deeper into the topic of enumeration and its applications in C programming, we recommend exploring the C programming language documentation and various online resources. Practice writing programs that involve enumeration and experiment with different scenarios to strengthen your understanding of this concept.

    We hope this blog post has provided you with valuable insights and tips for working with enumeration in C. Feel free to leave any comments or questions below. Happy programming!