Look And Say

<?php
$nums = '11225422';

function lookandsay($num)
{   $output = '';
    $firstCharPos = 0;
    $endCharPos = 0;
    for ($i = 0; $i < strlen($num); $i++) {
        if( substr($num, $firstCharPos, 1) != substr($num, $i, 1) )
        {
            $digitsTotal = substr($num, $firstCharPos, $endCharPos);
            $output .= strlen($digitsTotal) . ':' . substr($num, $firstCharPos, 1). ' ';
            $firstCharPos = $i;
            $endCharPos = 0;
        }
        $endCharPos = $endCharPos + 1;
    }
    $digitsTotal = substr($num, $firstCharPos, strlen($num));
    $output .= strlen($digitsTotal) . ':' . substr($num, $firstCharPos, 1). ' ';
    return $output;
}

echo lookandsay($nums);
?>