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Javascript Features

JavaScript is one of the most popular languages which includes numerous features when it comes to web development. It's amongst the top programming languages as per Github and we must know the features of JavaScript properly to understand what it is capable of.

Some of the features are lightweight, dynamic, functional and interpreted. Now we are going to discuss some important features of JavaScript.

  • Light Weight Scripting language

  • Dynamic Typing

  • Object-oriented programming support

  • Functional Style

  • Platform Independent

  • Prototype-based

  • Interpreted Language

  • Async Processing

  • Client-Side Validation

  • More control in the browser

Let's see all of these features in detail so that you can understand them. Some of the above-specified features are old JavaScript features while some of them are new features.

1. Light Weight Scripting Language

JavaScript is a lightweight scripting language because it is made for data handling at the browser only. Since it is not a general-purpose language so it has a limited set of libraries. Also as it is only meant for client-side execution and that too for web applications, hence the lightweight nature of JavaScript is a great feature.

2. Dynamic Typing

JavaScript supports dynamic typing which means types of the variable are defined based on the stored value. For example, if you declare a variable x then you can store either a string or a Number type value or an array or an object. This is known as dynamic typing.

To understand this, in languages like Java, we explicitly mention that a particular variable will store a certain type of data, whereas in JavaScript we do not have to provide the data type while declaring a variable. In JavaScript, we just have to use var or let keyword before the variable name to declare a variable without worrying about its type.

3. Object-Oriented Programming Support

Starting from ES6, the concept of class and OOPs has been more refined. Also, in JavaScript, two important principles with OOP in JavaScript are Object Creation patterns (Encapsulation) and Code Reuse patterns (Inheritance). Although JavaScript developers rarely use this feature but its there for everyone to explore.

3. Functional Style

This implies that JavaScript uses a functional approach, even objects are created from the constructor functions and each constructor function represents a unique object-type. Also, functions in JavaScript can be used as objects and can be passed to other functions too.

4. Platform Independent

This implies that JavaScript is platform-independent or we can say it is portable; which simply means that you can simply write the script once and run it anywhere and anytime. In general, you can write your JavaScript applications and run them on any platform or any browser without affecting the output of the Script.

5. Prototype-based Language

JavaScript is a prototype-based scripting Language. This means javascript uses prototypes instead of classes or inheritance. In languages like Java, we create a class and then we create objects for those classes. But in JavaScript, we define object prototype and then more objects can be created using this object prototype.

7. Interpreted Language

JavaScript is an interpreted language which means the script written inside javascript is processed line by line. These Scripts are interpreted by JavaScript interpreter which is a built-in component of the Web browser. But these days many JavaScript engines in browsers like the V8 engine in chrome uses just in time compilation for JavaScript code.

8. Async Processing

JavaScript supports Promise which enables asynchronous requests wherein a request is initiated and JavaScript doesn't have to wait for the response, which at times blocks the request processing. Also starting from ES8, Async functions are also supported in JavaScript, these functions don't execute one by one, rather they are processed parallelly which has a positive effect on the processing time, reducing it to a great extent.

9. Client-side Validations

This is a feature which is available in JavaScript since forever and is still widely used because every website has a form in which users enter values, and to make sure that users enter the correct value, we must put proper validations in place, both on the client-side and on the server-side. JavaScript is used for implementing client-side validations.

10. More control in Browser

JavaScript being a client-side language provides many features that help developers to divide processing between browser and server hence reducing the load on servers by having basic processing, validations, temporary data saving using cookies, etc on the browser itself.

Along with all these features, JavaScript provides the following useful features too:

  • Detecting browser type, name OS version, etc information of the client for analysis.

  • Extensive in-built library with many useful functions for validation, data type conversion, string operations, etc.

  • It is an object-centered language with Window Object being the most important object in JavaScript and it also supports Polymorphism.

  • Support for commonly used complex data types like array, Maps, List, etc. with support of in-built functions to operate on them.