不小心便學會了電腦

orginal:

form->{var} = undef;
my $var;
if($form->{var}){
$var = $form->{var};
}else{
$var = 1;
}

example:

my $var = $form->{var} ? $form->{var} : 1;

$var = $form->{var} || 1;