How to find the second-to-last occurrence of a character within a string?

Question

If possible, using only standard PHP functions like substr(), strrpos(), strpos(), etc.

Answer 1

First, find the last position:

$last = strrpos($haystack, $needle);
if ($last === false) {
  return false;
}

From there, find the 2nd last:

$next_to_last = strrpos($haystack, $needle, $last - strlen($haystack) - 1);

Answer 2

General solution for any number of backwards steps:

function strrpos_count($haystack, $needle, $count)
{
    if($count <= 0)
        return false;

    $len = strlen($haystack);
    $pos = $len;

    for($i = 0; $i < $count && $pos; $i++)
        $pos = strrpos($haystack, $needle, $pos - $len - 1);

    return $pos;
}