my %hash = ( foo => 1, bar => 2, baz => (), qux => 3);
print keys %hash;

##</code><code>##

my %data  = (

'email'=>scalar $cgi->param('user_email'),
'name'=>scalar $cgi->param('user_name'),
'cell_phone'=>scalar $cgi->param('user_cell_phone'),
'home_phone'=>scalar $cgi->param('user_home_phone'),
'work_phone'=>scalar $cgi->param('user_work_phone'),
);

##</code><code>##

my %data = ('email' => 'user_email', 'name' => 'user_name',
            'cell_phone' => 'user_cell_phone', 'home_phone' => 'user_home_phone',
            'work_phone' => 'user_work_phone');
$_ = $cgi->param($_) for values %data;