Функция PHP mb_strtoupper

string mb_strtoupper ( string str [, string encoding] )

mb_strtoupper returns str with all alphabetic characters converted to uppercase.

encoding specifies the encoding of str; if omitted, the internal character encoding value will be used.

By contrast to strtoupper, 'alphabetic' is determined by the Unicode character properties. Thus the behaviour of this function is not affected by locale settings and it can convert any characters that have 'alphabetic' property, such as a-umlaut (?).

Пример использования mb_strtoupper:

   $str = "Mary Had A Little Lamb and She LOVED It So";
   $str = mb_strtoupper($str);

See also strtoupper, mb_strtolower and mb_convert_case.