Preg_split creates an array, but makes it empty

Question

I would like to split a line of 3 characters with a dot between them, that is, I have a value of 12345678, I want to get 12.345.678 from it, here is my code:

function insertDocs($str) {
    $str = str_split($str);
    $str = array_reverse($str);
    $str = implode($str);
    $str1 = preg_split("/[0-9]{1,3}/u", $str);
    print_r($str1);
    $str1 = implode('.', $str1);
    $str1 = str_split($str1);
    $str1 = array_reverse($str1);
    $str1 = implode($str1);
    return $str;
  }
  echo insertDocs("12345678");

Here is what I get in return:

Array
(
    [0] =>
    [1] =>
    [2] =>
    [3] =>
)

This is print_r, and echo:

87654321

Tell me what I'm doing wrong, or tell me how to make it easier, I will be very grateful to you

Answer 1

As your first part depends on the total number of characters, this code first splits off the odd bit from the start, then uses str_split() with the remainder to split it into 3 character segments...

function insertDocs($str) {
    $start = substr($str, 0, strlen($str) % 3);
    $end = str_split(substr($str, strlen($start)), 3);
    array_unshift($end, $start);
    return implode(".", $end);
}

So

echo insertDocs("12345678");

gives...

12.345.678

To fix your original code, you could change the preg_split() line to

$str1 = str_split($str, 3);

and make sure you return $str1 from the function and not $str .