php - strtolower() for unicode/multibyte strings

Question

I have some text in a non-English/foreign language in my page, but when I try to make it lowercase, it characters are converted into black diamonds containing question marks.

$a = "????? ?????????";
echo $b = strtolower($a);
//returns  ????? ?????????

I've set my charset in a metatag, but this didn't fix it.

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

What can I do to convert my string to lowercase without corrupting it?

Answer 1

have your tried using mb_strtolower()?