Encapsulation and Information Hiding

Encapsulation and information hiding are important principles in object-oriented programming (OOP) that promote modular, maintainable, and secure code. Let’s explore each concept:

Encapsulation:

• Encapsulation is the bundling of data (attributes) and methods (functions) that operate on the data into a single unit, typically called a class.
• It allows for the abstraction of the internal state of an object, providing controlled access to its attributes and behaviors.
• Encapsulation helps in hiding the internal implementation details of an object and exposing only the necessary interfaces to interact with it.

Information Hiding:

• Information hiding is a specific aspect of encapsulation that refers to the practice of restricting access to certain parts of an object’s internal state or implementation details.
• It involves marking certain attributes or methods as private or protected, preventing direct access from outside the class.
• By hiding implementation details, information hiding promotes modularity and reduces dependencies between different parts of a system, making the code more robust and maintainable.

Example demonstrating encapsulation and information hiding:

class BankAccount {
    private $balance; // Private attribute

    // Constructor
    public function __construct($initialBalance) {
        $this->balance = $initialBalance;
    }

    // Method to deposit money
    public function deposit($amount) {
        if ($amount > 0) {
            $this->balance += $amount;
        }
    }

    // Method to withdraw money
    public function withdraw($amount) {
        if ($amount > 0 && $amount <= $this->balance) {
            $this->balance -= $amount;
        }
    }

    // Method to get the current balance
    public function getBalance() {
        return $this->balance;
    }
}

// Creating an instance of the BankAccount class
$account = new BankAccount(1000);

// Accessing the public method to deposit money
$account->deposit(500);

// Accessing the public method to withdraw money
$account->withdraw(200);

// Accessing the public method to get the balance
echo "Current balance: $" . $account->getBalance();

Explanation:

• In this example, the BankAccount class encapsulates the data (balance) and methods (deposit, withdraw, getBalance) related to managing a bank account.
• The $balance attribute is marked as private, hiding it from direct access outside the class. This ensures that the balance can only be modified through the deposit and withdraw methods, maintaining data integrity.
• Public methods like deposit, withdraw, and getBalance provide controlled access to the internal state of the object, allowing clients to interact with the bank account without directly accessing its private attributes.

By encapsulating data and hiding implementation details, encapsulation and information hiding enhance the security, maintainability, and flexibility of object-oriented code.