Question

I went through a few basics on preg match but its quite difficult when your new to it.

What im trying to do is search for this instance in a string

bug1234

it shouldnt be case sensitive so bug1234 or BuG1234 should work
it must be the word bug followed by any 4 numbers
there should be no spaces or anything in between bug1234 so bug-1234 should not be a match
it should ignore things like bug1234z and abug1234 so it must be bug1234 with nothing prefixing it or coming directly after it unless there is a space between then so “there is a problem with bug1234 that i cant solve” would be a match.

Just to clarify it can be any number not 1234 specifically but they must be 4 digits

Heres my lame attempt:

$file_string = $workdetails->text;
$file_string = strtolower($file_string);
$bugkey = "/bug[0-9]{4}/";
$nosey = preg_match($bugkey, $file_string);
if($nosey !== false) 
{
echo "We have a match baby!!"
}

That just seemed to return all sorts, empty string,s string with no mention of the word bug

Answer 1

Try changing the regex to:

/\bbug[0-9]{4}\b/i

The \b modifier will only match on a word boundary so that makes sure it doesn’t match things like abug1234, bug12345 or bug1234was bad. I also added the i modifier so it is case insensitive. You no longer need to use strtolower.

Also, preg_match typically returns an integer, and returns (int)0 if there is no match. It only returns FALSE on failure. Therefore you should change the match check to be:

if ($nosey > 0) {
// or just
if ($nosey) {