[Resolved] How to use this function

[phplearner]

I found the following 'function' for validating a ZIP code:

function validate_zipcode($zipcode) {
     return preg_match('/^[0-9]{5}([- ]?[0-9]{4})?$/', $zipcode);
}

I've been trying to figure out how to use it in a form where $shipzip is the ZIP Code:

if (isset($_POST['submit'])) { 

 $shipzip = $_POST['shipzip'];

 if($shipzip is invalid) { // Pseudo Code
 echo "Sorry, Inaccurate ZIP Code";
}
}

Thanks for any help with so I can understand how similar 'function' calls can work.

[LordShryku]

The preg_match will return 1 if it is good, 0 if it's bad, so for you

if (isset($_POST['submit'])) {  

   $shipzip = $_POST['shipzip']; 
   if(validate_zipcode($shipzip) == 0) {
      echo "Sorry, Inaccurate ZIP Code"; 
   } 
}

[PHPGuru2]

I don't recommend using preg or ereg to validate data since it is hard to find a mistake (people get stucked with errors). Instead, I usually use two input fields instead of one (prefix zipcode and suffix zipcode) and do something like this:

if (is_numeric($zip1) && strlen($zip1) == 5 && is_numeric($zip2) && strlen($zip2) == 4)
{
$zipcode = $zip1 ."-". $zip2;
}
else
{
echo ("Invalid Zipcode.");
}

[drawmack]

guru - that's why it's important to build an error checking library and thoroughly test those regex's exactly once.

I've been using the same one for 3 years now. When I changed from perl to php my regexs still worked with preg

[phplearner]

Thank you ALL for your solution options.

Much appreciated 😃