Question

What is encapsulation?

Short answer

Provide an example to illustrate the concept. Answer: Encapsulation is a key principle in object-oriented programming, where data and functions are wrapped up into a single unit called a 'class'. This hides and protects the internal state and behavior of objects from external interference. The benefits of encapsulation include modularity, data hiding, code reusability, and improved security. An example of encapsulation is the BankAccount class, which encapsulates account number and balance properties and provides methods to interact with these properties, ensuring the safety of the object's internal state.

Step-by-step solution

Encapsulation Definition

Encapsulation is a fundamental principle of object-oriented programming (OOP) where the internal state and behavior of objects are hidden and protected from external interference. It means wrapping up of data and functions into a single unit, known as a 'class'. The main goal of encapsulation is to promote modularity, maintainability, and security of code.

Benefits of Encapsulation

Encapsulation provides several benefits for code implementation and maintenance. Some of the key advantages are: 1. Modularity: Encapsulating the code within classes promotes modularity, making it easier to understand and maintain the code. 2. Data hiding: By restricting access to the internal state of an object, encapsulation prevents accidental changes or misuse of data. 3. Code reusability: Encapsulated code can be reused in different parts of the application or other applications without worrying about unwanted side-effects. 4. Improved security: Encapsulation enforces strict access control, making it more difficult for malicious code to exploit vulnerabilities in the system.

Example of Encapsulation

Let's consider an example to illustrate the concept of encapsulation using a simple Bank Account class. ```python class BankAccount: def __init__(self, account_number, balance): self.__account_number = account_number self.__balance = balance def deposit(self, amount): if amount > 0: self.__balance += amount def withdraw(self, amount): if amount > 0 and amount <= self.__balance: self.__balance -= amount def get_balance(self): return self.__balance def get_account_number(self): return self.__account_number ``` In this example, we have created a BankAccount class that encapsulates the account number and balance properties. Notice the use of double underscores before the attributes __account_number and __balance; this makes them private, preventing direct access from outside the class. The BankAccount class also defines methods for deposit, withdraw, and getting balance and account number. These methods act as interfaces to manipulate and access the encapsulated data, ensuring the safety of the object's internal state. In conclusion, encapsulation is a vital principle of object-oriented programming that promotes modularity, maintainability, reusability, and security in the code, making it easier to understand, implement, and maintain complex systems.