I have written following regular expression /^[A-Za-z0-9-_\s]*$/ in PHP which allows numbers, letters, spaces, hyphen and underscore. I want to display those matches which are not valid against the regex i.e "My Name is Blahblah!!!" should give me "!!!" output.
views:
73answers:
4
+9
A:
Use the caret symbol inside the character class to invert the match and remove the start (^) and end ($) characters:
/[^A-Za-z0-9-_\s]+/
http://php-regex.blogspot.com/2008/01/how-to-negate-character-class.html
Andy E
2010-07-21 13:59:50
You want to get rid of those anchors, and change the `*` to `+`. The OP is trying to pluck matches out of the string, not match the whole thing.
Alan Moore
2010-07-21 14:11:06
@Alan: yeah, the start and end anchors are gone. Thanks for the tip on the `+`, edited.
Andy E
2010-07-21 15:01:27
+2
A:
If you replace all the matches with the empty string then you'll get the non-matching parts back:
preg_replace('/[A-Za-z0-9-_\s]+/', '', $string)
This will work for any arbitrary regex, but for your specific regex @Andy's solution is simpler.
Notice that I removed the anchors ^ and $ to make this work.
John Kugelman
2010-07-21 14:00:03
You should change the `*` to a `+`. Otherwise you're going to waste a lot of time replacing nothing with nothing. ;)
Alan Moore
2010-07-21 14:06:15
A:
preg_replace("/^[A-Za-z0-9-_\s]*$/","","My Name is Blahblah!!!") // Output: "!!!"
Or, if you want all the groupings of them
preg_split("/^[A-Za-z0-9-_\s]*$/","","My Name is Blahblah!!!")
Jamie Wong
2010-07-21 14:01:35
+1
A:
You have to put the hiphen - at the begining or at the end of the character class or escape it, so your regex would be :
/[^-A-Za-z0-9_\s]+/
or
/[^A-Za-z0-9_\s-]+/
or
/[^A-Za-z0-9\-_\s]+/
M42
2010-07-21 18:21:07