use warnings;
use strict;

sub abc()
{
  $_ = 'x';
}

foreach(1..2)
{
    my $loopvar = 'in the loop';
  print "Before:$_\n";
  abc();
  print "After:$_\n";
}

print "\$_ = $_\n";  # warning for uninitialized value $_ (global scope)

abc();
print "\$_ = $_\n";  # prints $_ = x