HP Business BASIC/XL Reference Manual - HP 3000 MPE/iX Computer Systems - Edition 1 (32715-90001)

3- 41
function).
* No undeclared variables under OPTION DECLARE.
Syntax
[ALL ]
VERIFY [ [{,} ] ]
[
progunit [{;} progunit ]...]
Parameters
ALL Specifies all program units in the program, including
the main program unit. ALL is the default.
progunit One of the following:
[SUB] subunit_name .
[SUB] function_name .
[SUB]MAIN.
A program unit cannot execute unless it is well-formed . For this reason,
HP Business BASIC/XL verifies a program unit at the following times:
* At run time, if it was modified since its last call.
* Before saving it in a BASIC Save file.
Therefore, you do not need to issue the VERIFY command to check a program
before you run it, because HP Business BASIC/XL will issue it
automatically. The purpose of the VERIFY command is to allow you to
VERIFY a program as you develop it, without having to RUN or SAVE it.
Example
The following example shows what happens when a program is not
well-formed . The example below shows the results of the VERIFY command.
HP Business BASIC/XL has issued the VERIFY command when the programmer
typed RUN.
>10 OPTION DECLARE !This specifies that all variables must be declared
>20 WHILE A !A is not declared, and the WHILE statement
>25 !is not closed
>30 PRINT A
>RUN
Error 179
Structured constant on line 20 not properly closed.
Error 1403
Undeclared variable A found in subunit MAIN.
Error 157
VERIFY error(s) in program.
Calling External Subunits
External routines fall into the following categories:
* Procedures (routines that do not return values).
* Functions (routines that return values).