Example of an added Built-In Function making a difference

[Frank Ferrell]

UPDATE: 6-18-2003 -- Examples Improved. Acknowledgement follows in next post

Greetings --

When I went from MS-Qbasic to PowerBASIC DOS, I - like many a programmer before and after - was introduced to many new features and improvements.

One of those improvements was a built-in PowerBASIC function called REMOVE$. This one strips out any specified character from a given string.

For example, if a string called HX$ contains this "R o-bocop7", and you wanted to take out the space as well as the "-" and the "7", then you would have this line ..
HX$=Remove$(HX$, ANY "-7 ") which produces the result "Robocop"

Suppose you wanted to remove a character that normally couldn't be shown in the ANY part of the Remove$ function - say the quote " mark. Easy - you would have this line--
HX$=Remove$(HX$, any chr$(34))

-- and similar lines for other such characters.

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Thanx-A-Lot and Enjoy, Frank --My PB


[This message has been edited by Frank Ferrell (edited September 10, 2004).]

[Frank Ferrell]

Greetings --

A huge thanks to Kurt, a PowerBASIC member, for giving me a great tip on making the character-stripping routine in example-B (above post) MUCH simpler. Here's a copy of the e-mail he sent me.

Hi, Frank -

I've been reading your messages in the PB forum.

Regarding the "REMOVE$" function in PB4DOS, you can make your
examples even simpler.

You don't need the FOR/NEXT loop to cycle through the SELECT/CASE
block.  All you are doing is string manipulation, so use the
string manipulation tools.

Start by defining a string of what you want to allow:

LegalCharacters$ = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"

Fetch the input:

LINE INPUT, StringInQuestion$

Force it to upper case:

StringInQuestion$ = UCASE(StringInQuestion$)

Take everything that's legal out of the string under test:

Temp$ = REMOVE$(StringInQuestion$, ANY LegalCharacters$)

If there is anything left in the temporary string it is illegal
stuff,  and THAT's what you need to REMOVE$ from your
StringInQuestion$:

ProcessedString$ = REMOVE$(StringInQuestion$, ANY Temp$)

This should also (by default) handle the situation where no
'illegal' characters were put into Temp$ (because none existed in
the StringInQuestion$), so you don't need an IF THEN/ELSE/END IF
block that tests for LEN(Temp$) > 0.  In other words, the line
above should also work as desired if LEN(Temp$) = 0.

The end result of this module is something in the variable
"ProcessedString$"

Note that you could define non-alpha-cum-non-numeric characters
in your LegalCharacters$ if you so desire. If you wanted to allow
the double-quote mark, for example, you could append ' + CHR$(34)'
to the line defining the allowable stuff; other printing
characters could just be typed in with the rest of the literal
string; non-printing characters need to be specified by
concatenating their appropriate CHR$() values to the literal
string.

Kurt

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Thanx-A-Lot and Enjoy, Frank -- My PB

[This message has been edited by Frank Ferrell (edited June 21, 2003).]