As a programmer, you might be building a system which admits arbitrary user-supplied text. In that case, be very careful.
You might select a face that is really good for English text. It probably lacks Cyrillic or Greek coverage, or has inferior kerning in those blocks. В чащах юга жил бы цитрус? Да, но фальшивый экземпляр! See how Cyrillic text falls back to an alternate font.