3v4l.org

run code in 300+ PHP versions simultaneously
<?php $mystring = "something/2018/02/something_else"; if(preg_match("~/\d{4}/\d{2}/~",$mystring,$out)){ echo "Found: {$out[0]}"; }else{ echo "Date components not found"; }

preferences:
30.67 ms | 404 KiB | 5 Q