my $var;

sub foo {
  $var++;
}

##</code><code>##


sub foo {
  my $var;
  {
    $var++;
  }
}

##</code><code>##

sub foo {
  ...
}

sub bar {
  ...
}

my $var = 0;
foo();
bar();

##</code><code>##

main();

sub main {
  my $var = 0;
  foo();
  bar();
}

sub foo {
 ...
}

sub bar {
  ...
}