qw/STRING/

Returns a list of the words extracted out of STRING, using embedded whitespace as the word
delimiters. It is exactly equivalent to 

    split(' ', q/STRING/);

This equivalency means that if used in scalar context, you'll get split's (unfortunate)
scalar context behavior, complete with mysterious warnings. 

Some frequently seen examples: 


    use POSIX qw( setlocale localeconv )
    @EXPORT = qw( foo bar baz );

A common mistake is to try to separate the words with comma or to put comments into a
multi-line perlman:perlop-string. For this reason the -w switch produce warnings
if the STRING contains the ``,'' or the ``#'' character. 

##</code><code>##

split(' ',q/#FF0000 #00FF00 #0000FF/)

##</code><code>##

#!/usr/bin/perl -wT
use strict;

print "$_ " for (qw ( #FF0000 #00FF00 #0000FF ));
print "\n";
print "$_ " for (split(' ',q/#FF0000 #00FF00 #0000FF/));
print "\n";

=output
Possible attempt to put comments in qw() list at ./qw.pl line 4.
#FF0000 #00FF00 #0000FF 
#FF0000 #00FF00 #0000FF