Only Allowing Alpha Numeric

[livethedead]

I realise I can search the string by using preg_match_all (%+[a-zA-Z0-9]%, $string) but that's only matching a-z 0-9 not telling me if there's some σx or something else funky. Much obliged.

[Pikachu2000]

You haven't actually asked a question.

[livethedead]

Sorry that was unclear, I meant how to check if anything other than a-z 0-9 is in the string. I figured it out though incase any other newbie runs across the same question. If there's a better way I'm all for improving.

 

<?php
$regex = preg_match_all("%[a-zA-Z0-9]%", $str, $array);

if (strlen($str) > $regex) {
echo "only alpha or numeric combinations are allowed";
} else {
	echo "success!"; 
}
?>

[Pikachu2000]

You don't need to use a regex pattern for that at all.

 

if( ctype_alnum(str_replace(' ', '', $str)) ) {
     // only alphanumeric chars and spaces are in the string.
}

[livethedead]

Ahh thanks, google you have failed me! /sigh I was all stoked I even made my first function out of that code lol. Thanks much.

[Pikachu2000]

Generally, if you can accomplish a task with simple string functions, then don't bother with a regex pattern.

[AyKay47]

Generally, if you can accomplish a task with simple string functions, then don't bother with a regex pattern.

 

yes "livethedead" I agree with pika. While I do love regex, if there is a simple PHP functions solution to the problem, I would always go with that. Especially with large strings such as text files etc. They tend to be much more efficient than using a regular expression in most cases. It is only in special cases where the solution cannot be done with simple PHP functions or it would be way too much of an effort to do so where a regex should be used.

[livethedead]

Yeah I was thinking of that while I wrote it but, I couldn't seem to find that function so I ended up using regex, thinking it was my next-best choice.