How to check, if a php string contains only english letters and digits?
Use preg_match().
if (!preg_match('/[^A-Za-z0-9]/', $string)) // '/[^a-z\d]/i' should also work.
{
// string contains only english letters & digits
}
if(ctype_alnum($string)) {
echo "String contains only letters and numbers.";
}
else {
echo "String doesn't contain only letters and numbers.";
}