Add space after every 4th character

Question

I want to add a space to some output after every 4th character until the end of the string. I tried:

$str = $rows[\'value\'];


        

Answer 1

On way would be to split into 4-character chunks and then join them together again with a space between each part.

As this would technically miss to insert one at the very end if the last chunk would have exactly 4 characters, we would need to add that one manually (Demo):

$chunk_length = 4;
$chunks = str_split($str, $chunk_length);
$last = end($chunks);
if (strlen($last) === $chunk_length) {
    $chunks[] = '';
}
$str_with_spaces = implode(' ', $chunks);