- var_dump: documentation ( source)
- print_r: documentation ( source)
- preg_match_all: documentation ( source)
- array_filter: documentation ( source)
- preg_split: documentation ( source)
<?php
$str = 'a\\\\,b,c\\,d';
var_dump(preg_split('/(?<!(?<!\\\\)\\\\),/', $str));
preg_match_all('/[^\\\\]\\\\,|([^,]+?)/', $str, $matches);
print_r(array_filter($matches[1]));