ONSTARTprefix.md 1.9 KB

ONSTART prefix

Purpose: The ONSTART prefix specifies that the subroutine, which it prefixes, be called before any other procedure. Passing arguments to an ONSTART subroutine is not allowed.


 Syntax:

 ONSTART SUB SubName()
 ' do something before your code executes
 END SUB

 Parameters:

  • None

ONEXIT prefix

Purpose: The ONEXIT prefix specifies that the subroutine, which it prefixes, be called after all other procedures. Passing arguments to an ONEXIT subroutine is not allowed.


 Syntax:

 ONEXIT SUB SubName1()
 ' do something as your program exits back to OS
 END SUB

 Parameters:

  • None

Example 1:


 ? "This is a test of ONSTART and ONEXIT subroutines."
 ? "Notice that you don't have to explicitly call them?"
 ? "Also notice that ONSTART is called before any other"
 ? "code in your program and ONEXIT is called just before"
 ? "your program exits."
 
 ? "Both must be subs and neither may have any parameters."
 
 ? "These can be used to do initialing or cleanup code in"
 ? "your programs."
 
 
 ONSTART SUB XRay()
  ? ""
  ? "Hello !"
  ? ""
 END SUB
 
 ONEXIT SUB ZRay()
  ? ""
  ? "Goodbye ..."
  ? ""
 END SUB

Example 2:


  PRINT "Hello there!"
 PAUSE
 
 ONSTART SUB first()
  PRINT "Starting!"
 END SUB
 
 ONSTART SUB second()
  PRINT "Starting 2!"
 END SUB
 
 ONEXIT SUB myexit()
  PRINT "Goodbye !"
 END SUB