Number Format

Format a number with grouped thousands(please visit number_format in php):

function numberformat($str, $sep=',') {
    $result = '';
    $str = $str.'';
    $c = 0;
    $num = strlen($str);
    for($i=$num-1; $i>=0; $i--) {
        if($c==3) { 
            $result = $sep.$result;
            $result = $str[$i].$result;
            $c = 0;
        } else {
            $result = $str[$i].$result;
        } 
 
        $c++;
    }
 
  return $result;
}
 
//OUT = 1,333,555
echo numberformat(1333555);