How to find specific characters using PHP

Question

My task was to create a PHP file that will check a name coming from HTML GET and the basis are the following:

I don't know whether I will use REGEX or STRIPOS for this. My professor is asking me to write this in PHP. Some example scenarios:

1. AdriaN = allow
2. $tackoverFlow = not allowed
3. StackoverFl0w = allowed
4. ™ Stack Over Flow ™ = Allowed
5. StækOverFlow = not allowed

Here's what I have come up with so far, can this be improved upon?

 $pattern = '/[a-zA-Z0-9\$\™]{1,24}$/';

It can be from `a-b in small or capital letters` ?? You mean `a-z` ? Also `StackoverFl0w` has the number `0` so are numbers allowed as well? — hwnd, Aug 11 '14 at 23:36
Yes from a-z. A word with a combination of numbers are also okay. — Adrian Roy Baguio, Aug 11 '14 at 23:43
More details are needed... what about: http://regex101.com/r/mA1yU3/1 — Enissay, Aug 11 '14 at 23:47
Don't forget to tell your professor that it was @Enissay who solved the problem :) — Erlesand, Aug 11 '14 at 23:49
Will do, I will add your name to credits :) My version is $pattern = '/[a-zA-Z0-9\$\™]{1,24}$/'; It also works! — Adrian Roy Baguio, Aug 11 '14 at 23:55
@Enissay [this is a whole lot shorter](http://regex101.com/r/mA1yU3/2) — scrowler, Aug 11 '14 at 23:57
I thought a `$` was not permitted, but you have it in your code sample? — halfer, Aug 12 '14 at 00:46

revo · Accepted Answer · 2014-08-12T08:13:39.890

1

As your samples, you've some spaces inside that are allowed. So I suggest this regex:

/^[a-z\d™][a-z\d\s™]{1,24}(?<!\s)$/im

m multi-line and i case-insensitive modifiers are set

If Professor asks for (?<!\s), reply back it's a negative lookbehind to ensure that there's no trailing spaces at the end.

edited Aug 12 '14 at 08:13

answered Aug 12 '14 at 07:48

revo

1 Answers1