I just installed xxamp on my macbook air and I haven't used phpmyadmin on it yet, but when I go on localhost/phpmyadmin it says
MySQL said: Documentation
Cannot connect: invalid settings.
Connection for controluser as defined in your configuration failed.
phpMyAdmin tried to connect to the MySQL server, and the server rejected the connection. You should check the host, username and password in your configuration and make sure that they correspond to the information given by the administrator of the MySQL server.