Code Structure

CrossBasic uses block delimiters rather than braces to define scope. Proper organization and consistent indentation improve readability.

File Layout¶

A typical .xs file is structured as follows:

Module & Class Definitions
Global Variables & Constants
Function & Subroutine Declarations
Main Script Logic / Event Loop

' 1) Module Definition
Module AppConfig
  Public Const Version As String = "1.0"
End Module

' 2) Global Variables
Dim counter As Integer = 0

' 3) Subroutine & Function Declarations
Sub Initialize()
  counter = 0
End Sub

Function Increment(ByVal step As Integer) As Integer
  counter = counter + step
  Return counter
End Function

' 4) Main Script Execution
Initialize()
Print("Counter at start: " + Str(counter))

Dim newCount As Integer = Increment(5)
Print("Counter after increment: " + Str(newCount))

Block Delimiters¶

Block Type	Opening Keyword	Closing Keyword
Subroutine	`Sub Name(...)`	`End Sub`
Function	`Function Name()`	`End Function`
If Statement	`If ... Then`	`End If`
Select Case	`Select Case`	`End Select`
For Loop	`For ... To`	`Next`
While Loop	`While ...`	`Wend`
Do Loop	`Do` / `Do While` / `Do Until`	`Loop`

Indentation & Whitespace¶

Indent by two or four spaces (tabs are allowed but be consistent).
Indentation has no semantic effect—it’s purely for human readability.

If x > 0 Then
    Print("Positive")
ElseIf x < 0 Then
    Print("Negative")
Else
    Print("Zero")
End If

Case‑Insensitivity¶

Keywords, function names, and variable names are not case‑sensitive: Dim x As Integer, dim X as integer, and DIM x AS INTEGER are equivalent.