Statement for uncheck checkbox codeigniter

Statement for uncheck checkbox codeigniter

i want to do is a condition for unchecked. checkbox. only the
checked(checkbox) could be work for looping. And how do I stop the foreach
from running if a checkbox has not been checked?
sample looping. $count = (count($waybillno)>false);
for ($i = 0; $i < $count; $i++) {
$data = array(
'waybillno' => $waybillno[$i],
'quantity' => $quantity[$i],
'waybilldate' => $waybilldate[$i],
'declared_value' => $declared_value[$i],
'consignee' => $consignee[$i],
);