in reply to help me ---regarding string

The idea is to look for spaces on word boundaries and remove them (i.e it monitors the transition of a word character into a non-word character and then removes the non-word character), you can also monitor the transition of a non-word character into a word character by detecting the word character boundary post a non-word character as in the second line. 

$string = "H e l l o  P e r l p r i n t";
print $string for $string =~ s/\b[ ]//g; 
print $string for $string =~ s/[ ]\b//g;


UPDATE:added non-capturing square brackets to account for more efficie
+ncy after
 Anomalous Monk's enlightenment...

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An exercise question for you, what do you think the reason that running both the print lines above together would result in the following output, But running only a single line of either the two print statements works just fine?! 
Hello PerlprintHelloPerlprint

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Re^2: help me ---regarding string
by AnomalousMonk (Archbishop) on Oct 06, 2009 at 10:20 UTC
    Although perlprint asked only about blanks and letters, sometimes punctuation creeps in. The third alternative handles all non-blanks and avoids capturing: 
    >perl -wMstrict -le
"my $string = 'W h a t  H o ?  N o  G o .';
 (my $sqz1 = $string) =~ s{ [ ] \b }{}xmsg;
 print qq{'$sqz1'};
 (my $sqz2 = $string) =~ s{ \b [ ] }{}xmsg;
 print qq{'$sqz2'};
 (my $sqz3 = $string) =~ s{ [ ] (?![ ]) }{}xmsg;
 print qq{'$sqz3'};
"
'What Ho ? No Go .'
'What Ho?  No Go.'
'What Ho? No Go.'

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    Update:  (?![ ]) vice  (?=\S) in third example.
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