2011/2/10 terry peng <terry.p...@mail.ru>:
> does "return ()" mean return an empty list, or just mean "return" since "()"
> is optional in Perl?
I would have guessed an empty list, but the best way to find out is to
check. :) According to my tests, it's returning according to context:
#!/usr/bin/env perl
use strict;
use warnings;
use Data::Dumper;
sub test1
{
return ();
}
sub test2
{
return;
}
sub test3
{
my @empty_array = ();
return @empty_array;
}
my $scalar1 = test1;
my $scalar2 = test2;
my $scalar3 = test3;
my @array1 = test1;
my @array2 = test2;
my @array3 = test3;
print "\$scalar1: ", Dumper \$scalar1;
print "\$scalar2: ", Dumper \$scalar2;
print "\$scalar3: ", Dumper \$scalar3;
print "\@array1: ", Dumper \@array1;
print "\@array2: ", Dumper \@array2;
print "\@array3: ", Dumper \@array3;
__END__
Results:
$scalar1: $VAR1 = \undef;
$scalar2: $VAR1 = \undef;
$scalar3: $VAR1 = \0;
@array1: $VAR1 = [];
@array2: $VAR1 = [];
@array3: $VAR1 = [];
So it seems the only time an empty list is returned in scalar context
is when I returned an empty array. I think that `return ();` is
returning undef in scalar context, just as `return;` does.
--
Brandon McCaig <http://www.bamccaig.com/> <bamcc...@gmail.com>
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Castopulence Software <http://www.castopulence.org/> <bamcc...@castopulence.org>
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