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What's wrong with always quoting "$vars"?by faq_monk (Initiate) |
on Oct 08, 1999 at 00:20 UTC ( [id://606]=perlfaq nodetype: print w/replies, xml ) | Need Help?? |
Current Perl documentation can be found at perldoc.perl.org. Here is our local, out-dated (pre-5.6) version: The problem is that those double-quotes force stringification, coercing numbers and references into strings, even when you don't want them to be. If you get used to writing odd things like these:
print "$var"; # BAD $new = "$old"; # BAD somefunc("$var"); # BAD You'll be in trouble. Those should (in 99.8% of the cases) be the simpler and more direct:
print $var; $new = $old; somefunc($var); Otherwise, besides slowing you down, you're going to break code when the thing in the scalar is actually neither a string nor a number, but a reference:
func(\@array); sub func { my $aref = shift; my $oref = "$aref"; # WRONG }
You can also get into subtle problems on those few operations in Perl that
actually do care about the difference between a string and a number, such
as the magical Stringification also destroys arrays.
@lines = `command`; print "@lines"; # WRONG - extra blanks print @lines; # right
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