FreeBasic Enum Keyword

Last modified April 20, 2026

The FreeBasic Enum keyword defines an enumeration type, which contains a set of named constants. Enums make code more readable by replacing magic numbers with meaningful names.

Basic Definition

In FreeBasic, Enum creates a new type consisting of named integer constants. Each constant in the enumeration has an underlying integer value.

By default, the first enumerator has value 0, and each subsequent enumerator is incremented by 1. You can explicitly assign values to enumerators. Enums improve code clarity and maintainability.

Simple Enum Declaration

This example shows a basic enum declaration and usage.

Enum Days
 Sunday
 Monday
 Tuesday
 Wednesday
 Thursday
 Friday
 Saturday
End Enum
Dim today As Days = Wednesday
Print "Today is day number: "; today

Here we define a Days enum with seven constants representing weekdays. The first value (Sunday) gets 0, Monday gets 1, and so on. We declare a variable of type Days and print its numeric value.

Enum With Explicit Values

You can assign specific values to enum constants.

Enum HttpStatus
 OK = 200
 Created = 201
 Accepted = 202
 BadRequest = 400
 Unauthorized = 401
 NotFound = 404
End Enum
Dim response As HttpStatus = NotFound
Print "HTTP Status: "; response

This enum defines common HTTP status codes with their standard numeric values. We assign the NotFound value to a variable and print it. Using named constants makes the code more understandable than using raw numbers.

Enum With Bit Flags

Enums can be used to create bit flags for combining options.

Enum FilePermissions
 Read = 1
 Write = 2
 Execute = 4
End Enum
Dim myPermissions As FilePermissions = Read Or Write
If (myPermissions And Read) = Read Then
 Print "Read permission granted"
End If

This example shows how to use enums for bitwise operations. Each permission is a power of two, allowing combination with OR operations. We check for specific permissions using AND operations. This is common in system programming.

Enum In Switch Statement

Enums work well with Select Case statements for clear branching.

Enum TrafficLight
 Red
 Yellow
 Green
End Enum
Dim light As TrafficLight = Yellow
Select Case light
 Case Red
 Print "Stop"
 Case Yellow
 Print "Caution"
 Case Green
 Print "Go"
End Select

We define a traffic light enum and use it in a Select Case statement. The code becomes very readable as each case clearly describes the action for each light state. Enums eliminate magic numbers in such logic.

Enum With Custom Base Type

FreeBasic allows specifying the underlying type for an enum.

Enum SmallEnum As Byte
 Value1
 Value2
 Value3
End Enum
Enum LargeEnum As Integer
 BigValue1 = 100000
 BigValue2
 BigValue3
End Enum
Print "Size of SmallEnum: "; SizeOf(SmallEnum)
Print "Size of LargeEnum: "; SizeOf(LargeEnum)

Here we declare two enums with different underlying types. SmallEnum uses Byte (1 byte), while LargeEnum uses Integer (4 bytes). This can be useful for memory optimization or when needing larger enum values.

Enum As Function Parameters

Enums can be used as function parameters for type safety.

Enum LogLevel
 Debug
 Info
 Warning
 [Error]
 Critical
End Enum
Sub LogMessage(level As LogLevel, message As String)
 Print "["; level; "] "; message
End Sub
LogMessage(Info, "Application started")
LogMessage([Error], "File not found")

This example demonstrates using an enum as a function parameter. The LogMessage function accepts a LogLevel enum, ensuring only valid log levels can be passed. Note the brackets around Error as it is a FreeBasic keyword.

Enum With Methods

Enums can be extended with methods using the Extends keyword.

Enum Colors
 Red
 Green
 Blue
End Enum
Function Colors.ToString(c As Colors) As String
 Select Case c
 Case Red: Return "Red"
 Case Green: Return "Green"
 Case Blue: Return "Blue"
 End Select
End Function
Dim favorite As Colors = Green
Print "Favorite color: "; Colors.ToString(favorite)

Here we extend the Colors enum with a ToString method. This allows converting enum values to human-readable strings. The method is called using the enum type name followed by the method name.

Best Practices

• Naming: Use singular names for basic enums, plural for flags.
• Values: Only specify values when they have special meaning.
• Scoping: Prefix enum values if they might conflict.
• Documentation: Comment enum values that aren't self-explanatory.
• Type Safety: Use enums instead of integers when appropriate.

This tutorial covered the FreeBasic Enum keyword with practical examples showing its usage in different scenarios.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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