Remove double letters in a text string

Regular Expression Problem

[rfontaine]

Hi,

I have alot of text with double letters. Something like:

"add" should be "ad"

"allot" should be "alot"

ETC.

Being terrible at regular expressions I am looking for a preg_replace that replaces these double letters with just a single letter.

Any ideas on how this can be accomplished? It seems like a toughie -

Thank you in advance,
Ron

[rfontaine]

anyone?

[coopster]

Using a back reference [php.net] would work.

$string = "Hello there dubble letters!"; 
$pattern = "/([a-z])\\1/Uis"; 
$replacement = "$1"; 
print "$string<br />"; 
print preg_replace($pattern, $replacement, $string);

[rfontaine]

Well THAT is cool Coopster...didn't know about that, thank you Very much!

[ergophobe]

Sorry, but this is probably just not a job for regex unless you have a very particular situation (also note that "allot" is a valid English word, but "alot" is not). In the following versions, errors are bolded.

"I want to allot some serious money to adding a star-studded add campaign to our program that will help allot".

becomes

"I want to alot some serious money to ading a star-studed ad campaign to our program that will help alot".

Your regex takes a sentence with two errors and creates a sentence with four errors.

The correct version (uhh, in terms of spelling - it's still a terrible sentence of course) would be

"I want to allot some serious money to adding a star-studded ad campaign to our program that will help a lot".

[rfontaine]

Hi ergophobe,

It was just an example used to explain whatI needed - there is actually a larger problem that needed solving and figuring out how to do this particular thing is one step.

[ergophobe]

I figured that was just an example, but the same caveat applies. You have to make sure that you're not going to be grabbing all sorts of stuff you don't expect.

have fun!