- array_combine: documentation ( source)
- print_r: documentation ( source)
- preg_match_all: documentation ( source)
- str_word_count: documentation ( source)
<?php
$string = "2=OK, 3=OK" ;
preg_match_all('!\d+!', $string, $matches);
$res = array_combine($matches[0], str_word_count($string, 1));
print_r($res);