$INCLUDE

$INCLUDE is a metacommand that is used to insert a source code file into your program which is then executed at the point of the insertion.

Syntax

{REM | REM } $INCLUDE: 'sourceFile'

QBasic Metacommand must be commented with REM or an apostrophe.
The sourceFile name must be enclosed in apostrophes and can include a path.
$INCLUDE is often used to add functions and subs from an external text QBasic code library.
The $INCLUDE metacommand should be the only statement on a line.

Assemble the code to be reused into a file.
Common extensions are .BI (for declarations, usually included in the beginning of a program) or .BM (with SUBs and FUNCTIONs, usually included at the end of a program). ** Any extension can be used, as long as the file contains code in plain text (binary files are not accepted).
$INCLUDE any DIM, CONST, SHARED arrays or DATA at the beginning of the main program code.
$INCLUDE SUBs or FUNCTIONs at the bottom of the main program code after any SUB procedures. ** Note: TYPE definitions, DATA and DECLARE LIBRARY can be placed inside of sub-procedures.
Compile the program. *Note: Once the program is compiled, the included text files are no longer needed with the program EXE.

If an error occurs in an include file:

in addition to _ERRORLINE, the function [_INCLERRORLINE[(_INCLERRORLINE) also returns the number of which text line in the include file caused the error. It is 0 if an include file is not being executed.
the function _INCLERRORFILE$ contains the name of the include file where the error occurred. It is "" if an include file is not being executed.

** '$INCLUDE:** 'QB.BI'