Science Knowings: JavaScript Course For Social Media

Inheritance

Inheritance: Extending JavaScript's Capabilities

We left off with classes, a powerful tool for organizing and structuring code. Now, let's dive into inheritance, a concept that takes code reusability and extensibility to the next level!

What is Inheritance?

Inheritance is a mechanism that allows you to create new classes (child classes) based on existing classes (parent classes). Child classes inherit the properties and methods of their parent classes, enabling code reuse and extension.

Benefits of Inheritance

  • Code Reusability: Avoid code duplication by inheriting common functionality from parent classes.
  • Extensibility: Extend existing functionality by adding new methods and properties to child classes without modifying the parent class.
  • Hierarchy and Organization: Create a clear hierarchy of classes, organizing code based on relationships.

Code Example #1: Simple Inheritance

class Person {
constructor(name) { this.name = name; }
greet() { console.log(`Hello, ${this.name}!`); }
}
class Student extends Person {
constructor(name, major) {
super(name);
this.major = major;
}
study() { console.log(`${this.name} is studying ${this.major}.`); }
}

Parent vs. Child Classes

Parent Class: The class from which other classes inherit. It defines the common properties and methods.

Child Class: The class that inherits from the parent class. It can inherit and extend the parent's functionality.

Method Overriding

A child class can override methods inherited from the parent class. This allows you to provide a different implementation for the overridden method.

Super Keyword

The super keyword allows you to access the parent class from within the child class. It's used to call the parent's constructor or methods.

Types of Inheritance: Single Inheritance

A child class inherits from a single parent class.

Types of Inheritance: Multilevel Inheritance

A child class inherits from another child class, which in turn inherits from a parent class.

Types of Inheritance: Hierarchical Inheritance

Multiple child classes inherit from the same parent class.

Types of Inheritance: Multiple Inheritance (ES6)

ES6 introduced multiple inheritance, allowing a class to inherit from multiple parent classes.

Polymorphism: Same Method, Different Behavior

When a child class overrides a method from the parent class, the same method can have different behaviors in different classes.

Method Overloading

A class can have multiple methods with the same name but different parameter lists. This is known as method overloading.

Object Creation: A Deeper Dive

Objects are created using the new keyword. When an object is created, its constructor is called to initialize the object.

Object References and Cloning

Objects are passed by reference, not by value. Cloning an object creates a new object with the same properties and values.

Object Destruction

Object destruction allows you to extract specific properties from an object and assign them to variables.

Next Topic: Modules (import/export)

Modules allow you to organize code into reusable units. We'll explore how to import and export modules in JavaScript.

Follow us for more in-depth discussions and code examples to master JS modules!