regex question find pattern and replace part of pattern

[Semnomic]

Hi

 

Im struggling with this problem

I have a string, in this string I have a "-" followed by 10 random digits.

 

so eg.   $mystring =  cat-345-4345645678abcd-12abc

I can find the "-4345645678" with ([-][0-9]{10})|.
 

 I need to replace the "-" with an "xx"

the "-" I'm trying to replace MUST be followed by ten random numbers.

Any ideas ?

Edited September 20, 2017 by Semnomic

[Sepodati]

Like this?

 

<?php

$mystring =  'cat-345-4345645678abcd-12abc';

$newstring = preg_replace('/-([0-9]{10})/', 'xx$1', $mystring);

var_dump($newstring);

?>
Output: string(29) "cat-345xx4345645678abcd-12abc"

Edited September 20, 2017 by Sepodati

[Semnomic]

Yes thanks,

 

never used or seen var_dump so unsure on the way it outputs

 

Output: string(29) "cat-345xx4345645678abcd-12abc" ??

 

 

 

 

Thanks I will read up !!

Edited September 21, 2017 by Semnomic

[Sepodati]

It's just a detailed print. More useful for arrays, but I used it out of habit.

[requinix]

Another way is to make a regex that finds a "-" but only if it's followed by 10 digits.

preg_replace('/-(?=[0-9]{10})/', 'xx', $mystring)