Re: Reii: Should we Localize $

I don't get what you're saying. If you have a construct like while (<>) or foreach(@arr) you get a newly scoped $_:

sub doit
{
 my @array = qw(1 2 3 4);
 # this doesn't damage outer @array:
 $_ = 'xyz' foreach (@array);
}

my @array = qw(a b c d);
print join("|", @array), "\n";

foreach (@array)
{
 my $f = doit('abcd');
}

print join("|", @array), "\n";
[download]

Comment on Re: Reii: Should we Localize $_ ? Download Code

Replies are listed 'Best First'.
Re: Re: Reii: Should we Localize $_ ? by dragonchild (Archbishop) on Jun 13, 2001 at 23:52 UTC
Try the following with and without the 'local $_;' line and you'll see what he's talking about. use strict; sub getfile { local $_; my $filename = shift; local F; open F, "< $filename" or die "Couldn't open `$filename': $!"; my $contents; while (<F>) { s/#.//; # Remove comments next unless /\S/; # Skip blank lines $contents .= $_; # Save current (nonblank) line } return $contents; } my @array = ("base_tester", "Foo.pm"); foreach (@array) { my $filename = $_; my $f = getfile($filename); } print "@array\n"; [download] That's what I tried to see the effects, and I was rather surprised.	[reply] [d/l]
Reiv: Should we Localize $_ ? by John M. Dlugosz (Monsignor) on Jun 13, 2001 at 23:56 UTC
No, `while(<>)` does not create a newly scoped $_. Behold: `require 5.6.1; use strict; use warnings; my @array= (1,2,3,4,5); foo() foreach (@array); print "@array\n"; sub foo { while (<DATA>) { return } # silly, but makes a small example with little input. } __DATA__ clobbered clobbered clobbered clobbered clobbered` [download]	[reply] [d/l] [select]