New Javascript Class

Michael Zippo 04.11.2021

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JavaScript is based on prototypes. Each time you declare an object, a prototype property is created, which extends the properties and methods associated with that object.

In recent years, many JavaScript developers have been looking for ways to orient objects to embed. design objects in their code. This gave birth to a new type of object in JavaScript called a class that extends a prototype.

In this guide, we’ll discuss what classes are, why they’re used, and how you can implement a class in your code. We’ll give an example to get you started with classes.

What is a JavaScript class?

Classes are a way to declare a model for an object.

If you are familiar with object oriented programming languages, you will know that they are highly dependent on classes and objects. A class is like a template for a data type: it says what data can be stored and what methods can be accessed. An object is an instance of this class.

An example of a class would be Book. This class would contain the blueprint for what information could be stored on the books and how that data could be changed. An object could be a streetcar called desire, which is an individual book.

In JavaScript, classes are what we call syntactic sugar. The syntax of the classes is nice to have, but they do n’t necessarily add new functionality.

Classes are commonly used in modern JavaScript frameworks such as React and Next.js.

lessons in relation to Functions

If you remember one thing from this article, be it this one: classes are quite normal functions

the only difference between a class and a function expression is the way they are declared, functions use the keyword and classes use the class . technically keyword, you can declare a class without even using the class keyword

we can say that they are the same by creating two functions and printing their prototypes.

Our class and function expression returns:

function ()

the two our functions and classes use the same arc reading based on a prototype.

How do you define a class? which is a great question.

You can define a class using the keyword. Once you have defined a class, you can use the constructor () function to initialize it with default values.

Open a JavaScript console and paste this code:.

This creates a class called Book. Our class can store two values, Title and Author, which we defined in our class construction method. To create an object of this class, we could use this code:

We can retrieve the values ‚Äã‚Äãof our class as we would any object:

Our code returns:. One of the advantages of using classes on prototypes is that you can declare a method inside a class. This means that you don’t need to use the prototype syntax to add a new method to an existing function

Let’s take this example:.

We have declared a method called GetDetails () that exists within our class. It’s nice, because it keeps all of our code grouped together. We call our function GetDetails ():

Our code returns:

a desire called streetcar is a book written by Tennessee Williams

Lesson Inherit

As in any object-oriented structure, classes can inherit properties from other classes.

Inheritance refers to a process in which a child class can access the methods and data of a parent class. To inherit from a class, you can use the Extend keyword. Create a JavaScript file or open your JavaScript console and paste this code:

We’ve created a class called fiction that uses the class from the book we previously declared as a project. In our code, we used the super () keyword to inherit the title and values ‚Äã‚Äãfrom the author of the parent class, which is Book. So, we have defined a new attribute, fiction, whose value is set to true by default

Our code returns: true. The fiction class stores an element called fiction which is true by default. If we tried to access this value from an instance of the Book class, nothing will be returned. Indeed, "fiction" is accessible in our fiction class.

Getter and Setter

Get functions allow you to retrieve methods of a class. Setter functions allow you to change the value of a particular element in a class. These functions are indicated using the keywords get and together respectively

In this example, we’ve declared two methods called author. One of these methods allows us to retrieve the value of author; this is our get method. The other method allows us to change author value

We initialized an object named tra m and it gave the title A Streetcar Named Desire. We then have the author value Tennessee Williams using the composer we defined in our code.Finally, we printed out author value on the console using the play method.

Conclusion

Although classes do not correspond to new JavaScript functionality, they make writing functions easier to understand if you are used to object oriented programming.

Abstract classes of design based on a JavaScript prototype and make it appear more object oriented. The word "look" is crucial because, remember , classes are functions. Classes are nothing more than syntactic sugar.

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