Question

How can I set a default value such as “don’t have any information” instead of a blank in front end part using php or any means for optional field which not require user to fill in(full name, dob, address….) after they register on my page for future user’s adjustment. Thank you very much in advanced!

Answer 1

If the user leaves a field blank, the variable you receive in $_POST will be an empty string. So on the receiving page:

if ($_POST['name'] != "") {
    $name = $_POST['name'];
}
else {
    $name = "did not submit a name";
}
// then insert $name and your other form variables into your database...