How to check if letter is upper or lower in PHP?

Question

I have texts in UTF-8 with diacritic characters also, and would like to check if first letter of this text is upper case or lower case. How to do this?

Answer 1

Tried ?

$str = 'the text to test';
if($str{0} === strtoupper($str{0})) {
   echo 'yepp, its uppercase';
}
else{
   echo 'nope, its not upper case';
}

Answer 2

function starts_with_upper($str) {
    $chr = mb_substr ($str, 0, 1, "UTF-8");
    return mb_strtolower($chr, "UTF-8") != $chr;
}

Note that mb_substr is necessary to correctly isolate the first character.