On Jul 27, 11:34 pm, u...@stemsystems.com ("Uri Guttman") wrote:
> >>>>> "EW" == Erik Witkop <ewit...@gmail.com> writes:
>
> EW> I have spent half the day looking at map and I still don't get it.
>
> it is easier than you think.
>
> EW> I don't get the EXPR versus BLOCK and how I can treat them differently.
>
> that is mostly a syntax difference. you can have a single expression,
> then a comma then the list OR a {} block of code, NO comma and a
> list. the block allows you to declare variables, have multiple
> statements, etc. some always use a block and for simple expressions it
> is the same as the EXPR one.
>
> EW> I think I am close but my regex is not hitting.
>
> EW> @final_results = map { m/^[a-zA-Z0-9]{3,4}?$/$1/ } @just_cust_codes;
>
> you aren't GRABBING anything. this is not a map issue but a regex
> one. people showed you how to do this in replies. why didn't you use
> their code?
>
> secondly m// has TWO slashes, and you have 3. you are NOT doing a
> substitution but a simple grab. and you aren't even doing a grab as
> there are no parens. a regex in list context (like in a map) will return
> its grabs so map will return them. no need for any $1 stuff.
>
> EW> I see a lot of people use a question mark in there, but I am unsure why.
>
> EW> All I want is the regex above to be in $1 for me to access.
>
> no you don't. it will be returned if you just use the code others have
> posted. then ask how that code works. you are guessing and typing random
> noise in hope that something will work. you need to understand how
> regexes AND map work together.
>
> EW> Any help would be appreciated.
>
> EW> p.s. I read perldoc -f map, and checked my camel book. I am honestly at
> a
> EW> loss.
>
> did you read perldoc perlretut? and then perldoc perlre? the issue is
> more regex than map.
>
> uri
>
> --
> Uri Guttman ------ u...@stemsystems.com -------- http://www.sysarch.com--
> ----- Perl Code Review , Architecture, Development, Training, Support ------
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Thanks everyone. I missed the earlier posts with the code. That worked
beautifully.
There is one more task that I am unable to solve.
If $_ was something like FYUY or fO76, I would like to remove the
first ^[Ff].But keep the last 3 character.
Find and Replace does not work obviously as I would lose those last 3
characters that I want. I researched the map functionality and I can't
come up with the proper code.
This doc is very good at explaining map.
http://mailman.linuxchix.org/pipermail/courses/2003-November/001368.html
But I don't see how I can still keep the last 3 characters.
I tried thinking of it in different way. I tried to do something like:
@map_results1 = map(/(^[^Ff]{3})/, @map_results1);
Basically saying, if it starts with NOT F or f, then grab 3
characters. Well that didn't work at all. But I understand how map
works, a little better from trying new things.
Any help on how I can remove F or f and still keep the last 3
characters in $_?
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