<?php function convDigit($str, $num = 3) { $str = strrev(strval($str)); $ret = ""; for ($i=0; $i< strlen($str); $i++){ if ($i && $i%$num == 0){ $ret = "/".$ret; } $ret = $str{$i}.$ret; } return $ret; }
1=> 1
12=> 12
123=> 123
1234=> 1/234
12345=> 12/345
123456=> 123/456
1234567=> 1/234/567
12345678=> 12/345/678