What is a JavaScript Class?

We explore the definition of a JavaScript Class and look at how they can be used to create reliable and reusable code.

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What is a Class?

Classes are a template for creating objects. A class is like an object constructor, or a “blueprint” for creating objects. Creating a class is similar to creating any other object in JavaScript.

What is an Object?

In JavaScript, an object is a collection of key/value pairs. A key is also known as a property, and a value can be a function, object, or anything else you can imagine.

What is a Prototype?

In JavaScript, a prototype is an object that defines the properties and methods for a given type of object. When you create an object, you can specify its prototype as the prototype property of the object’s constructor function. The resulting object will then have all the properties and methods defined in the constructor function’s prototype property.

For example, let’s say you have a constructor function for a Person type, which takes a name and age as parameters. You can then create an instance of this type as follows:

var p = new Person(“John Doe”, 30);

This person object will now have all the properties and methods defined in the Person constructor function’s prototype property.

What is a JavaScript Class?

A class is a type of object-oriented programming that is used to encapsulate data and methods within a single unit. In other words, it is a template for creating objects. Classes are often used in programming to model real-world objects, such as cars or animals.

What are the features of a JavaScript Class?

Classes are a template for creating objects. A class encapsulates data for the object.
JavaScript classes introduced in ECMAScript 2015 are syntactical sugar over JavaScript’s existing prototype-based inheritance. The class syntax is not an object-oriented programming language but rather a way to produce predicate logic based on first-class functions and object composition.

A class declaration creates a new class with a given name and body. The body of a class is executed in strict mode.

A class declaration creates two variables:
1)a reference to the constructor function used to create instances of the class.
2)a property descriptor for the prototype that exposes the inherited members of the superclass.

What are the benefits of a JavaScript Class?

JavaScript Classes offer a number of benefits over traditional JavaScript programming. Classes encourage code reuse and modularity. Code in a class can be reused in other projects, making development faster and more efficient. In addition, classes promote information hiding, which helps to protect code from accidental modification. Finally, classes make code easier to understand and maintain.

How do I use a JavaScript Class?

The JavaScript Class is a new feature in the JavaScript language that provides a class-based object-oriented programming model. In other words, the JavaScript Class provides a way to create objects and define their properties and methods. It also provides a way to inherit from other objects.

What is a Class declaration?

In object-oriented programming, a class is an extensible program-code-template for creating objects, providing initial values for state (member variables) and implementations of behavior (member functions or methods). … In many languages, the class name is used as the name for the class (the template itself), the name for the default constructor of the class.

What is a Class expression?

A Class expression is a way of defining a Class in JavaScript.

Class expressions can be named or unnamed. The name given to a named Class expression is only available within the Class body.

class Rectangle {
constructor(height, width) {
this.height = height;
this.width = width;

What is the difference between a JavaScript Class and a function?

There are a few key differences between a JavaScript class and a function. First, a class is a blueprint for an object, while a function is a self-contained unit of code. A class definition can contain properties and methods, while a function can only contain code. Secondly, classes are typically used to model real-world objects, while functions are used to perform specific tasks. Finally, classes can be extended or inherited from, while functions cannot.


As we have seen, a JavaScript class is a type of function that creates a new object. Classes can be defined using the class keyword, and can contain methods and properties that are shared by all objects created from the class. In addition, classes can be subclassed to create more specialized types of objects.

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