Variables
Symbols representing data in memory.
Description
Variables are name symbols which can be manipulated. They are declared and referenced using names composed of letters, numbers, and character "_". These reference names cannot contain most other symbols because such symbols are part of the FreeBASIC programming language. They also cannot contain spaces. See Indentifier Rules.
In FreeBASIC, variables can be defined using the `Dim` statement.
Variables are available for later access depending on where and how the `Dim` declaration for that variable is given. Depending on the scope of a variable, a defined variable can be available within the main area of a program, within a procedure, through an entire module, or through out an entire program. See Variable Scope.
Variables are also made available when they are passed as parameters to a procedure such as `Function` or `Sub`.
After a variable is declared with the `Dim` statement, they can be assigned, passed to procedures, and used in expressions wherever their Standard Data Type is similar. Sometimes variables are automatically converted to other data types before being used in expressions, or passed as parameters to procedures. See Coercion and Conversion.
Example
`
' compile with -lang qb or fblite
'$lang: "qb"
Declare Sub PrintConstants()
Dim FirstNumber As Integer
Dim Shared SecondNumber As Integer
FirstNumber = 1
SecondNumber = 2
PrintConstants ()
Print FirstNumber, SecondNumber, ThirdNumber 'This will print 1 2 0
Sub PrintConstants ()
Dim ThirdNumber As Integer
ThirdNumber = 3
Print FirstNumber, SecondNumber, ThirdNumber 'This will print 0 2 3
End Sub
`
See also

- Coercion and Conversion
- `Dim`
- Identifier Rules
- Variable Scope