如何使用strlen并检查最小和最大字数

Question

I am trying to use the code below and not sure if the second syntax will work as well. Is there also a way to check to see if an user has typed consecutive letters such as "aaaaaaaaaabbbbbbbbbbbbb" etc?

 if(strlen($joined)<200 || strlen($joined) > 500) {

              header("Location: index.php?reply_registration_form=invalidlength");
        exit(); 

Can I also do this?

  if(strlen($joined)<200 || $joined > 500) {

              header("Location: index.php?reply_registration_form=invalidlength");
        exit();

Answer 1

you can use preg_replace

<?
   php echo preg_replace("/(.)\\1+/", "$1", "aaaaaaaabbbbbbbbb"); // shows 'ab'
?>