Localizing the default pattern-matching space ($_) can make subroutines that perform several pattern-matching or other string operations against the same variable a lot quicker to write and easier to read and maintain.

I'd rather write: 

local $_ = shift;
s/\A[ \t]+//;
s/[ \t]+\z//;
tr/a-zA-Z0-9//cd;
return unless length;
...

[download]
than: 
my $x = shift;
$x =~ s/\A[ \t]+//;
$x =~ s/[ \t]+\z//;
$x =~ tr/a-zA-Z0-9//cd;
return unless length $x;
...

[download]

Am I being lazy? Yeah, that's part of it, but it's exactly that sort of idiom (if that even qualifies as idiomatic) that I expect to see in Perl code.

In reply to Re: Re: Using $_ as a temp var, especially in functions by converter
in thread Using $_ as a temp var, especially in functions by BUU

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