This

Hidden instance parameter passed to non-static member functions in a Type 
or Class

Syntax
   This.fieldname
or
   With This
      .fieldname
   End With

Description
   This is a reference to an instance of a Type or Class that is passed 
   (through a hidden Byref Parameter) to all non-static member functions of 
   that type or class. Non-static member functions are procedures declared 
   inside the body of a Type or Class and include Sub, Function, Constructor
   , Destructor, assignment or Cast Operator, and Property procedures.

   The This additional parameter also has the same data type as the Type or 
   Class in which the procedure is declared. Therefore using it corresponds 
   to referring to the instance declared name on which the non-static 
   member function is called.

   The This parameter can be used just like any other variable, ie., pass 
   it to procedures taking an object of the same type, call other member 
   procedures and access member data using Operator . (Member Access), etc.

   Most of the time, using This explicitly for member access is 
   unnecessary; member procedures can refer to other members of the 
   instance which they are passed directly by name, without having to 
   qualify it with This and Operator . (Member Access). The only times when 
   you need to qualify member names with This is when the member is 
   shadowed, for example by duplicating its name for a local variable or 
   parameter. In these situations, qualifying the member name is the only 
   way to refer to these masked member names.

Example
   Type sometype
      Declare Sub MyCall()
      value As Integer
   End Type

   Dim example As sometype

   '' Set element test to 0
   example.value = 0
   Print example.value

   example.MyCall()

   '' Output should now be 10
   Print example.value

   End 0

   Sub sometype.MyCall()
      This.value = 10
   End Sub

Differences from QB
   * New to FreeBASIC

See also
   * Base
   * Class
   * Type

