Are there any potential pitfalls when using ctype functions to check for character types in PHP?

One potential pitfall when using ctype functions to check for character types in PHP is that they are not multibyte safe, meaning they may not work correctly with multibyte characters. To solve this issue, it is recommended to use the mb_ctype functions from the mbstring extension, which are multibyte safe.

// Using mb_ctype functions for multibyte safe character type checking
$string = "こんにちは";
if (mb_ctype_alpha($string)) {
    echo "The string contains only alphabetic characters.";
} else {
    echo "The string contains non-alphabetic characters.";
}