C enum (Enumeration)
In C, an enum (short for "enumeration") is a user-defined data type that represents a set of named integer constants. Enums are used to make code more readable and self-explanatory by giving meaningful names to values that have a logical relationship.
SyntaxThe values within the enum are represented as integer constants, where value1 is 0, value2 is 1, and so on.
Defining an Enum
Here's an example of defining an enum to represent the days of the week:
Assigning Values to Enum Constants
By default, the first value in an enum is assigned 0, and each subsequent value is incremented by 1. However, you can explicitly assign values to enum constants:
In this example, January is assigned a value of 1, and subsequent months are automatically incremented by 1.
Using Enum Constants
You can use enum constants in your code to make it more readable and self-explanatory.
Here, currentDay is set to the enum constant Wednesday.
Switch Statements with Enums
Enums are often used in switch statements to improve code readability.
Size of Enums
The size of an enum constant is typically an int. If you need a smaller or larger data type, you can explicitly specify it.
In this case, the enum SmallEnum uses an unsigned char data type for its constants.
Enum Constants as Flags
Enums are often used to create flag values that can be combined with bitwise operations.
This allows you to use enums to represent and manipulate sets of flags.
Conclusion
enum in C is a convenient way to create named integer constants, improving code readability and maintainability. Enums can be used for representing sets of related values, and they are often used in switch statements, as flag values, or in situations where it's important to give meaningful names to numeric constants.