$foo = bar(@params);  
# You don't know what value $foo has
{
    local $foo = 1;
    foo(); 
}
sub foo { print "foo: $foo\n"; }
# now $foo is restored!

##</code><code>##

{
    local $Data::Dumper::Terse = 1;
    $baz = Dumper($data);
}