static function Part($string, $start, $length = null)
    {
        self::InitEncoding();
        if ($length !== null)
            return mb_substr($string, $start, $length);

        return mb_substr($string, $start);
    }
static function Part($string, $start, $length = null)
    {
        self::InitEncoding();
        if ($length !== null)
            return mb_substr($string, $start, $length);

        return mb_substr($string, $start);
    }
static function Part ( $ string , $ start , $ length = null ) { self :: InitEncoding ( ) ; if ( $ length !== null ) return mb_substr ( $ string , $ start , $ length ) ; return mb_substr ( $ string , $ start ) ; }
Returns length of string.
@param $string
@return int
Returns length of string .