Generating a random password in php

I am trying to generate a random password in php. However I am getting all 'a's and the return type is of type array and I would like it to be a string. Any ideas on how to correct the code? Thanks. function randomPassword() { $alphabet = "abcdefghijklmnopqrstuwxyzABCDEFGHIJKLMNOPQRSTUWXYZ0123456789"; for ($i = 0; $i < 8; $i++) { $n = rand(0, count($alphabet)-1); $pass[$i] = $alphabet[$n]; } return $pass; }