Regex word boundary alternative

Question

I was using the standard \b word boundary. However, it doesn't quite deal with the dot (.) character the way I want it to.

So the following regex:

\b(\w+)\b

will match cats and dogs in cats.dog if I have a string that says cats and dogs don't make cats.dogs.

I need a word boundary alternative that will match a whole word only if:

it does not contain the dot(.) character
it is encapsulated by at least one space( ) character on each side

Any ideas?!

P.S. I need this for PHP

score 6 · Accepted Answer · answered Dec 28 '12 at 18:57

6

You could try using (?<=\s) before and (?=\s) after in place of the \b to ensure that there is a space before and after it, however you might want to also allow for the possibility of being at the start or end of the string with (?<=\s|^) and (?=\s|$)

This will automatically exclude "words" with a . in them, but it would also exclude a word at the end of a sentence since there is no space between it and the full stop.

answered Dec 28 '12 at 18:57

Niet the Dark Absol

320,036
81
464
592

Thanks. Any way I could include words at the beginning and end of a sentence as well?! I might not need it, but it might just be good to know. – ObiHill Dec 28 '12 at 23:26

Shiplu Mokaddim · Answer 2 · 2012-12-28T19:14:09.307

2

What you are trying to match can be done easily with array and string functions.

$parts = explode(' ', $str);
$res = array_filter($parts, function($e){
   return $e!=="" && strpos($e,".")===false;
});

I recommend this method as it saves time. Otherwise wasting few hours to find a good regex solution is quite unproductive.

edited Dec 28 '12 at 19:14

answered Dec 28 '12 at 19:09

Shiplu Mokaddim

56,364
17
141
187

I need this as part of another regex as a first step of a `preg_replace` function so it won't quite work for what I need to do – ObiHill Dec 28 '12 at 21:52
Then its better to ask what you need actually. There might be better solution than regex. – Shiplu Mokaddim Dec 28 '12 at 22:03

Regex word boundary alternative

2 Answers2

Linked