When you are splitting and joining strings you can often end up with unwanted special characters such as spaces, tabs or line returns.  In stringjoin.php there is a simulated example.  Save that file as stringtrim.php

Note that it reports the password length as 9 rather than 8 because there is a space at the end.  It is surprisingly common for users to accidentally add that space at the end so add this code under the line which sets the value of $password:

$password=trim($password);

Try it and the password should now be reported correctly.  The trim() function removes any invisible characters at the beginning or end of a string.  You will use trim again soon.