preg_match lookbehind after second slash - php

Question

This is my string:
stringa/stringb/123456789,abc,cde
and after preg_match:
preg_match('/(?<=\/).*?(?=,)/',$array,$matches);
output is:
stringb/123456789
How can I change my preg_match to extract the string after second slash (or after last slash)?
Desired output:
123456789

Answer 1

You can match anything other than a / as
/(?<=\/)[^\/,]*(?=,)/
[^\/,]* Negated character class matches anything other than , or \
Regex Demo
Example
preg_match('/(?<=\/)[^\/,]*(?=,)/',$array,$matches);
// $matches[0]
// => 123456789

Answer 2

This should do it.
<?php
$array = 'stringa/stringb/123456789,abc,cde';
preg_match('~.*/(.*?),~',$array,$matches);
echo $matches[1];
?>
Disregard everything until the last forward slash (.*/). Once the last forward slash is found keep all the data until the first comma((.*?),).

Answer 3

You don't need to use lookbehind, i.e.:
$string = "stringa/stringb/123456789,abc,cde";
$string = preg_replace('%.*/(.*?),.*%', '$1', $string );
echo $string;
//123456789
Demo:
http://ideone.com/IxdNbZ
Regex Explanation:
.*/(.*?),.*
Match any single character that is NOT a line break character «.*»
Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
Match the character “/” literally «/»
Match the regex below and capture its match into backreference number 1 «(.*?)»
Match any single character that is NOT a line break character «.*?»
Between zero and unlimited times, as few times as possible, expanding as needed (lazy) «*?»
Match the character “,” literally «,»
Match any single character that is NOT a line break character «.*»
Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
$1
Insert the text that was last matched by capturing group number 1 «$1»