comment on

Your "nulls" weren't nulls at all. They arn't spaces either. They are just cases where your regex didn't match, so it didn't return anything. + Requires at least one occurence of the thing it is quantifiying. So if you say "A B" =~ /A(.+?)B/ you'll get a hit, because there is at least one thing between the A and B. If you do "AB" =~ /A(.+?)B/ it wont match because there isn't at least one thing between A and B. * however matches 0 or more things, so it would match in both cases.

use strict;
use warnings;

print "A-B =~ /A.+B/ --> ";
print "worked" if "A-B" =~ /A.+B/;
print "\n";

print "A-B =~ /A.*B/ --> ";
print "worked" if "A-B" =~ /A.*B/;
print "\n";

print "AB =~ /A.+B/ --> ";
print "worked" if "AB" =~ /A.+B/;
print "\n";

print "AB =~ /A.*B/ --> ";
print "worked" if "AB" =~ /A.*B/;
print "\n";
[download]

Outputs:

A-B =~ /A.+B/ --> worked
A-B =~ /A.*B/ --> worked
AB =~ /A.+B/ -->
AB =~ /A.*B/ --> worked
[download]

___________
Eric Hodges

In reply to Re^3: Null scalars in array by eric256
in thread Null scalars in array by Smaug

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		`&`
	<		`<`
	>		`>`
	[		`[`
	]		`]`

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.


laziness, impatience, and hubris
	PerlMonks