Encapsulation Data Hiding

Encapsulation

Bundling data with methods, controlling access via modifiers.

Encapsulated Class

public class BankAccount {
    private double balance; // Data hiding
    
    public double getBalance() {
        return balance;
    }
    
    public void deposit(double amount) {
        if (amount > 0) {
            balance += amount;
        }
    }
}

Key Points

• private: class only, protected: package+subclasses.
• Getters/setters provide controlled access.
• Prevents invalid data, improves maintainability.
• Access order: public > protected > default > private.