Further to davido's point about alternation:
Because it's a point that often escapes people (it's escaped me often enough), I want to emphasize that the effective low precedence of the  | (alternation) regex operator means that the  [A-Z].[a-z] portion of the OPed regex matches independently of the rest of that particular regex. E.g., after fixing the  // delimiter confusion, but leaving the  . (dot) matching as it was: 

>perl -wMstrict -le
"my $li = 'foo';
 ;;
 print qq{matched '$&' in '$li'}
   if $li =~ m{http://www.[a-z]|[A-Z].[a-z]}i;
"
matched 'foo' in 'foo'

[download]

NB: Don't get into the habit of using the  $& $` $' special matching variables in your regexes. See the paragraph in perlre that begins "WARNING: Once Perl sees that you need one of $&, $`, or $' anywhere in the program ..." for a discussion of the cost of using them, and also the following paragraph for a workaround available in Perl version 5.10+. Also see the discussion of these variables in perlretut for workarounds using substr that can be used pre-5.10.

In reply to Re^2: how to do match www.jkghfdjbh.org from $li? by AnomalousMonk
in thread how to do match www.jkghfdjbh.org from $li? by virudinesh

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