inheritance.php

<?php

// Example 1: -----------------------------------------------------------------
// Context:
// We have multiple user types that all share a number of methods and properties,
// instead of copying and pasting the things that these user types share, we can
// simply create a parent class that contains shared properties and function.

class User
{
  // Properties
    protected $username; // protected so it can be shared across child classes
    protected $password;
  // Methods
    public function setUsername($username)
    {
        $this->username = $username;
    }
    public function getUsername()
    {
        return $this->username;
    }
    public function setPassword($pass)
    {
        $this->password = $pass;
    }
    public function login($pass)
    {
        if ($this->password === $pass) {
            echo PHP_EOL . 'Welcome back' . PHP_EOL;
        } else {
            echo PHP_EOL . 'Wrong password, please try again.' . PHP_EOL;
        }
    }
}

class Admin extends User
{
    public function whoami()
    {
        return 'An System Admin';
    }
}
$admin = new Admin();

class Creator extends User
{
    public function whoami()
    {
        return 'A content creator';
    }
}
$creator = new Creator();


// Simulation 1
echo 'Creating new admin ... ' . PHP_EOL;
// Set username and password
$admin->setUsername('sysadmin1');
$admin->setPassword('test123');
// Test login function
echo 'New admin has been created with the name: ' . $admin->getUsername() . PHP_EOL;
echo PHP_EOL . 'Login attempt 1' . PHP_EOL;
$admin->login('test');
echo PHP_EOL . 'Login attempt 2' . PHP_EOL;
$admin->login('test123');

// Simulation 2
echo 'Creating new user ... ' . PHP_EOL;
// Set username and password
$creator->setUsername('Tami');
$creator->setPassword('test123');
// Test login function
echo 'New user has been created with the name: ' . $admin->getUsername() . PHP_EOL;
echo PHP_EOL . 'Login attempt 1' . PHP_EOL;
$creator->login('test');
echo PHP_EOL . 'Login attempt 2' . PHP_EOL;
$creator->login('test123');