#! perl -w
use strict;
my @test = ( 0,1,2,3,4,5,6,7,8,9);

print 'OK'.$/ if defined( @test[0 .. $#test] );

$test[5] = undef;

print 'OK'.$/ if defined( @test[0 .. $#test] );

@test[0 .. $#test] = (undef, undef, undef, undef, undef, undef, undef, undef, undef, 1);

print 'OK'.$/ if defined( @test[0 .. $#test] );

$test[$#test] = undef;

print 'OK'.$/ if defined( @test[0 .. $#test] );

__END__
# Output
C:\test>test.pl
OK
OK
OK

C:\test>