Access Modifiers & Getters & Setters

In the last lesson, we learned how to create a class with properties, methods and a constructor. In this lesson, we will learn about visibility and access modifiers. Let's look at the class that we created in the last lesson:

class User
{
  public $name;
  public $email;

  public function __construct($name, $email)
  {
    $this->name = $name;
    $this->email  = $email;
  }

  public function login()
  {
    echo 'The user logged in.';
  }
}

We have all of our properties and methods set to public. This is one of the three available visibility modifiers in PHP. Let's look at all of them and how they work:

• public - The property or method can be accessed from anywhere. This is the default visibility modifier. If we do not add any visibility modifier to a property or method, it will be set to public by default.
• protected - The property or method can be accessed from within the class and any class that inherits from it.
• private - The property or method can only be accessed from within the class.

So let's initialize a user and access the name property:

$user1 = new User('John Doe', 'john@gmail.com');

echo $user1->name; // John Doe

Now let's create a new property called status, set the value to active and set it to private:

class User
{
  public $name;
  public $email;
  private $status = 'active';

  public function __construct($name, $email)
  {
    $this->name = $name;
    $this->email  = $email;
  }

  public function login()
  {
    echo 'The user logged in.';
  }
}

Create a new user:

$user1 = new User('John Doe', 'john@gmail.com');

and let's try to access the status property outside of the class:

echo $user1->status; // Fatal error: Uncaught Error: Cannot access private property User::$status

As you can see, we get an error. This is because the property is private. If you try and set it from outside the class, you will get the same error. Let's try it:

$user1->status = 'inactive'; // Fatal error: Uncaught Error: Cannot access private property User::$status

If you change the visibility to protected, you will get the same result. However, if we were to inherit from the User class, we would be able to access the status property from within the child class. We will look at inheritance in the next lesson.

Getters & Setters

You can not directly access the private and protected properties and methods, however, you can create a public method in the class that can access the private property.

Add this method:

 public function getStatus()
  {
    echo $this->status;
  }

Now, use that method on your user:

$user1->getStatus(); // active

This works because getStatus is public and it is within the User class, so it has access to the status property. So this method GETS the property value.

Setters

At the same time, we can have a public method that let's us set the private property.

Add this method:

// Setter
public function setStatus($status)
{
  $this->status = $status;
}

Now you can use that in the global scope:

$user2->setStatus('inactive');
$user2->getStatus(); // inactive