Question

Write a class called TV with the following attribute. Name of the company and Screen size using super keyword and Inheritance to create a color TV class, it has a attribute TVtype also a BW TV class it is also have TVtype attribute in Boolean data type.

Short answer

Define `TV` class, then inherit it to create `ColorTV` and `BWTV` using the `super` keyword to initialize inherited attributes.

Step-by-step solution

Define the Base Class 'TV'

Create the base class called `TV`, which will have two attributes: `company_name` and `screen_size`. The constructor of this class will initialize these attributes.

Initialize 'TV' Class Constructor

In the constructor of the `TV` class, use the `__init__` method to set the `company_name` and `screen_size` from the parameters passed during object creation.

Define 'ColorTV' Class with Inheritance

Create a subclass called `ColorTV` inheriting from `TV`. This class should have an additional attribute `TVtype`, which can be anything that describes color TV, such as `"Color"`. Use the super keyword to call the `__init__` method of the `TV` class.

Initialize 'ColorTV' Class Constructor

Within the `ColorTV` constructor, use `super().__init__(company_name, screen_size)` to initialize the inherited attributes, and then add `self.TVtype = 'Color'`.

Define 'BWTV' Class with Inheritance

Create another subclass called `BWTV` inheriting from `TV`. This class should also have a `TVtype` attribute, but it will be in Boolean form (e.g., `True` for black and white TV). Again, use the super keyword here.

Initialize 'BWTV' Class Constructor

Within the `BWTV` constructor, use `super().__init__(company_name, screen_size)` to initialize the inherited attributes, then set `self.TVtype = True` or `self.TVtype = False` as required.

Key concepts

Java Inheritance

In Java, inheritance is a powerful feature that allows a new class, referred to as a subclass, to acquire the properties and behaviors (methods) of an existing class, known as a superclass. This concept helps in reusing existing code, making it more efficient and organized.
A subclass in Java inherits from a superclass using the `extends` keyword. By doing so, it gains access to the fields and methods of the superclass, which it can also modify or extend if necessary.

• This feature supports hierarchical classification. For example, a `ColorTV` can be a subclass of a more general `TV` class.
• It allows code reusability, as the common functionality does not need to be repeated.

Using inheritance, you can create a structured and organized codebase that is easy to read and maintain. By classifying objects into a hierarchy, Java handles complex relationships seamlessly.

classes and objects

In Object-Oriented Programming, a class serves as a blueprint for creating instances known as objects. Imagine a class as a detailed description or a plan for objects.
Classes define the properties (often called attributes) and behaviors (methods) that the objects created from the class will have. For instance, a `TV` class might have attributes such as `company_name`, and `screen_size` and methods to change channels or increase volume.

• An object is an instance of a class. When you create or 'instantiate' a class, you create an object with its own unique set of data that is defined by the class.
• In Java, once a class is defined, you can create objects using the `new` keyword, like `TV myTV = new TV("Sony", "55 inches");`.

Understanding classes and objects is crucial in Java as they form the foundation of Object-Oriented Programming, enabling the creation of scalable and maintainable applications.

super keyword

The `super` keyword in Java is used to refer to the immediate parent class object. It plays a crucial role when dealing with inheritance, particularly during the initialization of objects from a subclass.
The `super` keyword allows a subclass to access methods and properties of its superclass. Most importantly, it's used to call the constructor of the superclass, ensuring that the base class is properly initialized before the subclass adds its own functionality.

• For example, in the `ColorTV` class, `super(company_name, screen_size);` calls the constructor of the `TV` class, passing the parameters required for initializing its attributes.
• The `super` keyword helps avoid code duplication by leveraging existing functionality in a superclass, promoting a cleaner and more efficient code design.

The use of `super` ensures that every level of your object's hierarchy is initialized correctly, preventing errors and redundancy in your programming efforts.

constructor initialization

Construction initialization in Java revolves around preparing a new object to run properly by initializing its newly allocated memory. It is often handled in a special method known as a constructor.
Constructors have the same name as the class and have no return type. Their purpose is to set up the initial state of an object, binding it with the values passed during its creation.

• In the context of inheritance, when creating a subclass object, it's vital to ensure that both the superclass and subclass constructors are called.
• The `super` keyword is used in subclass constructors to invoke the parent class constructor, ensuring that all necessary initializations are provided.
• For example, in the `ColorTV` constructor: `super(company_name, screen_size)` initializes `ColorTV` with the attributes defined in the `TV` class.

Proper constructor initialization safeguards the integrity of objects, ensuring they are ready for use with their intended characteristics right from creation.