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

