Hello! In this lesson, we're revisiting Encapsulation, Private Attributes, and Private Methods in Object-Oriented Programming (OOP). Imagine encapsulation as an invisible fence safeguarding a garden from outside interference, keeping data and methods safe within. Within this garden, certain plants (Private Attributes and Private Methods) are only for the gardener's eyes. These are crucial for making your classes more robust and secure!

Encapsulation in OOP wraps up data and methods into a class. This organizational approach tidies the code and reinforces security. If you were to code a multiplayer game, for example, you could create a Player class, encapsulating data (health, armor, stamina) and methods (receiveDamage, shieldHit, restoreHealth).

Now, $player is an instance of the Player class on which you can call methods.

In PHP, the private access specifier designates attributes or methods as private. Private members are only accessible within the same class. Unlike some other languages, PHP class members are public by default.

Private attributes and methods are inaccessible directly from an instance in non-member functions. This arrangement helps maintain integrity.

Private Attributes, which can only be altered via class methods, limit outside interference. For instance, a BankAccount class might feature a balance private attribute that one could change only through deposits or withdrawals.

Here, $balance is private, thus ensuring the integrity of the account balance.

Like private attributes, private methods are accessible only within their class. Here's an example:

Here, addYearlyInterest is a public method that calls the private method addInterest.

Great job refreshing your understanding of encapsulation, private attributes, and private methods concepts in PHP! Correctly understanding and applying these foundational principles of OOP make your code concise, robust, and secure.

Coming up next is hands-on practice. Keep up the good work — exciting exercises are just around the corner!