Classes, Inheritance, and Constructors in JavaScript
In JavaScript, classes are templates for creating objects and can include constructors to initialize properties andmethods to perform actions. Additionally, inheritance can be used to share properties and methods between classes.
Syntax:
Classes in JavaScript are defined with the classkeyword, and constructors are defined with the `constructor` keyword. Inheritance is handled with the `extends` keyword.
A basic example of a class with a constructor and a method is as follows:
class Animal {
constructor(name) {
this.name = name;
}
greetings() {
console.log(`Hello, I´m a ${this.name}`);
}
}
const dog = new Animal("Dog");
dog.greetings();Example explanation:
- Class definition: The `Animal` class is defined using theclass keyword.
- Constructor: The constructor function is automatically executed when a new instance of the class is created. In this case, it initializes the name property with the value passed when creating the instance.
- Method: The class has a method called greetings, which prints a personalized message using the name property.
- Instance: An instance of the `Animal` class is created with the name "Dog", and then the greetings method is called, which prints to the console: `Hello, I´m a Dog`.
Purpose:
- Define classes that structure objects with properties and methods.
- Use constructors to initialize properties when creating instances of a class.
- Implement inheritance to share functionality between different classes.
- Facilitate the creation of complex data structures in JavaScript.
Exercises
The rest of the content is available only for registered and premium users!
JavaScript Concepts and Reference
Functions
Objects in JavaScript
Arrays
DOM (Document Object Model)
Error Handling
Promises and Asynchronicity
Modules in JavaScript
ES6 and Advanced Features
How many types of inheritance are there in JavaScript? What is inheritance in JavaScript? What are constructors in JavaScript? What are classes and inheritance? JavaScript classes examples JavaScript inheritance Classes in JavaScript JavaScript class methods JavaScript constructor Classes in JavaScript OOP Mozilla javascript class in javascript can a variable be declared without giving it a value.