Encapsulation

Encapsulation involves bundling the data (attributes) and methods (functions or behaviors) that operate on the data within a single unit, i.e., a class. It restricts access to certain components, hiding the internal state of an object from the outside, and exposing only the necessary functionalities through well-defined interfaces.

In C++ and Java, the encapsulation aspect is showcased through the use of access modifiers.

1. Private -> restrict access to class members only within the same class where they are declared. They are not accessible from outside the class.
2. Public -> allow unrestricted access to the class members from anywhere in the program.
3. Protected -> provide access to the class members within the same class and subclasses (classes that inherit from the parent class).

C++

class Smartphone {
    private:
        std::string brand;
            std::string color;
            int memory;
        float screen_size;

    public:
        void powerOn() {

        }
};

Java

public class SmartPhone {
    private String brand;
    private String color;
    private int memory;
    private float screenSize;

    public void powerOn() {

    }
}

Python

class SmartPhone:
    def __init__(self, brand, color, memory, screen_size):
        self._brand = brand  # Use a single underscore to indicate a "protected" attribute
        self._color = color
        self._memory = memory
        self._screen_size = screen_size

    def power_on(self):
        pass

Attributes are made private in a class to keep them hidden and secure inside, preventing direct access or modification from outside the class. On the other hand, methods are often made public to provide controlled ways to interact with and modify these private attributes.

In Python

Encapsulation is achieved through naming conventions and properties. Although Python doesn't have explicit access modifiers like Java (public, private), it uses a convention to indicate the level of visibility.

• Attributes (_brand, _color, _memory, _screen_size) are prefixed with a single underscore, indicating that they are intended for internal use (protected).

Exercise

What to do?

Create a Class of Product, with attributes:

• name,
• productId (int),
• price (double),
• inStock (boolean)

and a method to display the product detail.
Implement the concept of encapsulation that you’ve just learned!

Create an Object of Product and then call the method.