3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = 'a,b,c,d,e'; $arr = explode( ',', $str); $last = array_pop( $arr); $arr[] = array_pop( $arr) . $last; echo implode( ',', $arr);

preferences:
44.76 ms | 402 KiB | 5 Q