how to match postal code against range of postal codes

I have a unique problem that will probably require an expert answer.

I'm building a custom store for a canadian product and they want people from certain postal codes to not be able to ship to at all because the shipping costs are too high.

Fedex provided us with the list of postal codes in the "too far" range but they provided the data like this:

k1h > k9a
e42
j2n > l9t

so, my first though was to just print out every single possibility and stick it in a big array, not very efficient (at all)

I need a php function that can tell me whether or not the first 3 characters of the postal code are in between the start and end postal code

like

function check_postal($start,$end,$string)

it should also only check one code if start and end are the same value

can someone help me with this?
transitnetworkAsked:
Who is Participating?
 
Justin MathewsCommented:
PHP comparison operators can be used for lexical comparison also - meaning it will compare character by character until a difference is spotted. Then the word that has the character with the higher ascii code is considered greater than the other word.
0
 
Justin MathewsCommented:
Is this what you are looking for?
<?php
function check_postal($start,$end,$string)
{
	$start = strtoupper($start);
	$end = strtoupper($end);
	$string = strtoupper($string);
	$sub = substr($string, 0, 3);
	return ($sub>=$start && $sub<=$end);
}


if (check_postal('k1h', 'k9a', 'k4a78'))
   echo "High shipping cost area";

?>

Open in new window

0
 
transitnetworkAuthor Commented:
you're on the right track but i need the code to know that it goes [a-z][1-9][a-z] with ranges...

I am looking at your code and I don't see how it could know that k4a was actually between k1h and k9a

know what I mean?
0
Cloud Class® Course: SQL Server Core 2016

This course will introduce you to SQL Server Core 2016, as well as teach you about SSMS, data tools, installation, server configuration, using Management Studio, and writing and executing queries.

 
transitnetworkAuthor Commented:
Also for those not familiar with canadian postal codes and how they are structured here is a short detailed description available from the creator:
http://www.canadapost.ca/tools/pg/manual/PGaddress-e.asp#1413985
0
 
transitnetworkAuthor Commented:
very interesting, I will test your code!
0
 
Ray PaseurCommented:
I copied the "too far" list verbatim from the post above.  This will get you the right answers, I think.

I didn't know Canada had 850,000 postal codes! ~Ray
<?php // RAY_temp_postal.php
error_reporting(E_ALL);
echo "<pre>";



// CHECK FOR POSTAL CODES WE DO NOT WANT http://en.wikipedia.org/wiki/Postal_codes_in_Canada
function bad_postal_code($code)
{
    // AN ARRAY OF POSTAL CODE PAIRS FROM THE SHIPPING COMPANY
    $codes = array
    ( 'k1h > k9a'
    , 'e42'
    , 'j2n > l9t'
    )
    ;

    // NORMALIZE FIRST THREE CHARACTERS TO UPPERCASE
    $test_code = strtoupper(substr(trim($code), 0, 3));

    foreach ($codes as $bad)
    {
        // NORMALIZE ALL DATA TO UPPERCASE
        $bad_array = explode(' > ', strtoupper($bad));

        // ENSURE WE HAVE A TWO-ELEMENT RANGE TO TEST
        if (!isset($bad_array[1])) $bad_array[1] = $bad_array[0];

        // RETURN TRUE IF THE POSTAL CODE IS BETWEEN THE VALUES
        if ( ($test_code >= $bad_array[0]) && ($test_code <= $bad_array[1]) ) return TRUE;
    }
    return FALSE;
}



// TEST THE FUNCTION
$c = 'e41';    if (bad_postal_code($c)) echo PHP_EOL . "$c IS BAD";
$c = 'e42';    if (bad_postal_code($c)) echo PHP_EOL . "$c IS BAD";
$c = 'j2m';    if (bad_postal_code($c)) echo PHP_EOL . "$c IS BAD";
$c = 'l8t';    if (bad_postal_code($c)) echo PHP_EOL . "$c IS BAD";
$c = 's7h4K1'; if (bad_postal_code($c)) echo PHP_EOL . "$c IS BAD";

// A DIFFERENT LOOK
$c = 'e41';    if (!bad_postal_code($c)) echo PHP_EOL . "$c IS GOOD";
$c = 'e42';    if (!bad_postal_code($c)) echo PHP_EOL . "$c IS GOOD";
$c = 'j2m';    if (!bad_postal_code($c)) echo PHP_EOL . "$c IS GOOD";
$c = 'l8t';    if (!bad_postal_code($c)) echo PHP_EOL . "$c IS GOOD";
$c = 's7h4K1'; if (!bad_postal_code($c)) echo PHP_EOL . "$c IS GOOD";

Open in new window

0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.