Comparing German string in PHP file

I have code like this:

$rowTitle = trim($row->children(0)->plaintext);
echo $rowTitle;
if (strcmp($rowTitle, 'Bügellänge in mm') == 0) {
    echo 4;

rowTitle is from another German site, but
I copied from rowTitle from this echo $rowTitle, when I run code and paste it in if statement and after that strcmp doesn’t return 0.

Is the problem in my file and editor or where is it ? It is UTF-8.

Source: stackoverflow-php