Create a Random String In PHP

$characters = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
$randstring = '';
for ($i = 0; $i < 10; $i++) {
$randstring .= $characters[rand(0, strlen($characters))];
}
echo $randstring;