class UserAuth { function __construct($username, $password){ // code here } }In this code, the __construct method takes two parameters: $username and $password. These parameters are used to set the initial values of the class properties like user ID and password. Another example of using the __construct method for authentication is in the popular library, Laravel's Illuminate\Auth\GuardHelpers package. In this package, the methods are used to write custom authentication middleware that can be used in applications. In conclusion, the PHP Auth __construct method is a powerful tool for initializing custom authentication classes or middleware in PHP applications. It helps in defining the properties of a class and setting the default values for user credentials.