Leespunten in getallen

<?php
function addCommas($num, $crct) {	
	$len = strlen($num);
	$str[] = substr($num, -3);
	$j = -6;
	
	for($i = -3; (($i * -1) -3) < $len; $i -=3) {
		$str[] = substr($num, $j, $i) . $crct;
		$j -= 3;
	}
	
	$arr = array_reverse($str);
	$str = "";
	
	foreach($arr as $var) {
		$str .= $var;
	}
	
	$len = strlen($str) -1;
	$str = substr($str, 1, $len);
	return $str;
}

$num = 1234567892;

echo "Number org : ".$num."<br>";	
echo "Number new : ".addCommas($num, ".");
?>