Replacing whitespaces with a regex

Dr Manhattan has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Replacing whitespaces with a regex by choroba (Cardinal) on Mar 04, 2013 at 09:54 UTC
Just do `$words =~ s/\s\s+$/ /;` [download] whithout any `if`. If there is multiple whitespace, it will be replaced, if not, nothing happens. لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l] [select]
Re: Replacing whitespaces with a regex by Enlil (Parson) on Mar 04, 2013 at 10:15 UTC
`for ( @array ) { s/\s\s+$/ / }` [download] or `s/\s\s+$/ / for @array;` [download] since essentially you are testing all the words to see if they fit the pattern anyhow.	[reply] [d/l] [select]
Re: Replacing whitespaces with a regex by Anonymous Monk on Mar 04, 2013 at 10:43 UTC
Small variation of the previous solutions, replace any spaces (even 1 space) with 1 space: `for ( @array ) { s/\s+$/ / }` [download]	[reply] [d/l]
Re: Replacing whitespaces with a regex by ggoebel (Sexton) on Mar 04, 2013 at 13:51 UTC
When you have the time read perlre If you're in a rush... skip down to the section on "Quantifiers". TIMTOWTDI. Pick the way which you think you'll stand the best chance of understanding 3 weeks or 3 months from now when you're asked to tweak your code. Both: `$work =~ s/\s+$/ /; # more than once` [download] and `$work =~ s/\s{2,}$/ /; # at least twice` [download] should work.	[reply] [d/l] [select]
Re^2: Replacing whitespaces with a regex by soonix (Canon) on Mar 04, 2013 at 14:16 UTC
that should read "once or more" instead of "more than once" ++ anyway :-)	[reply]
Re: Replacing whitespaces with a regex by ISAI student (Scribe) on Mar 04, 2013 at 16:24 UTC
There is, of course, more than 1 to do it. My favorite is: `map {s/\s+$/ /} @array;` [download] It uses the @array, which makes the code more readable, and PERL's great map function for 1 liners.	[reply] [d/l]
Re^2: Replacing whitespaces with a regex by choroba (Cardinal) on Mar 04, 2013 at 16:44 UTC
map in a void context can be replaced by `for`: `s/\s+$/ / for @array;` [download] لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l] [select]
Re^3: Replacing whitespaces with a regex by ISAI student (Scribe) on Mar 04, 2013 at 17:16 UTC
`Yes. But map brings me memories of the times I got to know the PERL magic, +and more than 1 way to do it. If I use for or foreach, I feel like I +use TCL/Python, and not enjoying an experience unique to PERL. map seems, to me, as more decidedly PERLISH that for. It's a personal thing, and this is why I have said that it is a person +al prefernce (unless there is a performance consideration).` [download]	[reply] [d/l]
Re^4: Replacing whitespaces with a regex by topher (Scribe) on Mar 05, 2013 at 01:58 UTC
Re^5: Replacing whitespaces with a regex by ISAI student (Scribe) on Mar 20, 2013 at 18:47 UTC
Re: Replacing whitespaces with a regex by tmharish (Friar) on Mar 04, 2013 at 14:25 UTC
The essence is that you are using regex to match - but what you want to do is use `s/regex/replace/` to replace. Details on how to do it in your case has been covered extensively above.	[reply] [d/l]


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