What are some potential issues with using the str_word_count function in PHP, especially when dealing with special characters like 'ö'?

When using the str_word_count function in PHP to count words in a string containing special characters like 'ö', the function may not recognize these characters as word boundaries, leading to inaccurate word counts. To solve this issue, you can use the mb_str_word_count function, which supports multibyte character encoding and can correctly handle special characters like 'ö'.

$string = "This is a string with special characters like ö";
$word_count = mb_str_word_count($string);
echo $word_count;