How to make cyrillic chars upper case?

Question

So how do I get cyrillic chars to upper case?

echo strtoupper("русские");

this doesn't work.

Answer 1

Use mb_strtoupper with correct encoding (without it it won't work):

echo mb_strtoupper("русские", "utf-8");
РУССКИЕ

Answer 2

You will have to use MultiByte functions:

mb_strtoupper

Make sure that MB is installed and enabled in your PHP ;)