How do I make sure that a username/password only contains numbers letters and underscores?


$username
$password

if(preg_match('/^[a-zA-Z0-9_]*$/',$username)){
// Followed the rules
}else{
// Didn't do so
}

Originally Posted by Insensus

if(preg_match('/^[a-zA-Z0-9_]*$/',$username)){
// Followed the rules
}else{
// Didn't do so
}

thank you ^^