PHP string functions not working as expected on numbers cast as string

Question

I have the following code which places a space in postcode.

(string)$postcode = $row['postcode'];
$first = substr($postcode, strlen($postcode)-3);
$second = substr($postcode, strlen($first));
$postcode = $first . ' ' . $second;

The code works fine for most codes, except some. ie

PN45HA 70448

And i can't understand why? Can anyone shine a light on this?

Thankyou

`(string)$postcode = $row['postcode'];` should be: `$postcode = (string)$row['postcode'];` — Yoshi, Jul 28 '11 at 15:21
What is your expected and what the actual output? (give two examples, one working, one erroneous) — Select0r, Jul 28 '11 at 15:21
Input might be something like HX37NN and Output something like HX3 7NN, ie a space 3 spaces from the right in every postcode — whistlegull, Jul 28 '11 at 15:23

Yoshi · Answer 1 · 2011-07-28T15:34:39.843

4

Don't really understand the question, but if it's about the space, this will work:

$postcode = 'PN45HA70448';
$postcode = substr($postcode, 0, -3) . ' ' . substr($postcode, -3);
// PN45HA70 448

edited Jul 28 '11 at 15:34

answered Jul 28 '11 at 15:22

Yoshi

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huh? I guess from the format that it is already a string so it shouldn't matter. – Karoly Horvath Jul 28 '11 at 15:24
Yep the position of the cast makes no difference. Something like because there's lots of different types of postcodes – whistlegull Jul 28 '11 at 15:27
Thanks Yoshi - a lot quicker. – whistlegull Jul 28 '11 at 15:57

score 0 · Answer 2 · answered Jul 28 '11 at 15:28

0

$first = substr($postcode, 0, -3);
$second = substr($postcode, -3);
$postcode = $first . ' ' . $second;

answered Jul 28 '11 at 15:28

Karoly Horvath

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score 0 · Answer 3 · answered Jul 28 '11 at 15:34

$code = 'PN45HA 70448'
$first = substr($postcode, strlen($postcode)-3); // 448
$second = substr($postcode, strlen($first)); // PN45HA 70
$postcode = $first . ' ' . $second; // PN45HA 70 448

The problem is that not all of your postcodes are simple 6 character postcodes. You're simply adding space before the last 3 characters in whatever string you happen to pass in.

What you may need to do is use a regex:

$code = preg_replace('/([A-Z][0-9][A-Z])\s*([0-9][A-Z][0-9])/', '\1 \2', $code);

This'll take any string which looks like a postcode, with optional spaces between the two halves, and puts in a single space.

PHP string functions not working as expected on numbers cast as string

3 Answers3