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Javascript Features

JavaScript is one of the most popular programming languages which includes numerous features when it comes to web development. It's amongst the top programming languages as per Github and as per StackOverflow's Developer survey. So you must learn JavaScript and you should 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

  • Single-threaded

  • Async Processing

  • Web Workers

  • Client-Side Validation

  • More control in the browser

  • Backend development

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 in the browser or the client side.

  • Because JavaScript is meant for client-side execution 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 in JavaScript 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.

For example,

// below we have created a variable with string value
let str = "Studytonight"

3. Object-Oriented Programming support

  • Starting from ES6, the concept of class and OOP is better defined.

  • Also, in JavaScript, two important principles with OOP in JavaScript are:

    • Object Creation Patterns (Encapsulation)

    • Code Reuse patterns (Inheritance)

  • Although JavaScript developers rarely use these features, it's there for everyone to explore.

3. Functional Style

  • This implies that JavaScript uses a functional approach, even objects can be created using 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.

  • Many important JavaScript concepts and features like callbacks, closures, etc. are implementations of functions only.

4. Platform Independent

  • This implies that JavaScript is platform-independent or we can say it is portable.

  • This 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 an 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.

  • The JS code is 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 use just-in-time compilation for JavaScript code.

8. Single threaded

  • JavaScript doesn't support multi-threading, by default it is single-threaded, which means it can execute only a single task at a time.

  • But JavaScript provides some features using which you can implement parallel execution. They are:

    • Async processing

    • Web workers

9. Async Processing

  • JavaScript supports Promise which enables asynchronous requests wherein a request is initiated and JavaScript doesn't have to wait for the response if a request takes time and may block 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.

10. Web Workers

  • Using Web workers you can run processes in background threads so that you can have parallel execution.

  • If you have any task that performs some heavy-duty work, then you can use a Web worker to run it in the background.

11. Client-side Validations

  • This is a feature that has been available in JavaScript since the beginning 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.

12. 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 arrays, Maps, lists, etc. with support of in-built functions to operate on them.

13. Backend Development

With NodeJS, backend development can also be done using JavaScript. MERN stack is one of the most popular stacks based on JavaScript for Fullstack Development using JavaScript. ExpressJS can be used for API or REST service development. NodeJS brings in npm which is a package manager for JavaScript modules, hence you can use 3rd party packages too, making the backend development even more fun and easy in JavaScript.

Read Also: Java vs JavaScript: What is the Difference Between Java and JavaScript?

About the author:
I like writing content about C/C++, DBMS, Java, Docker, general How-tos, Linux, PHP, Java, Go lang, Cloud, and Web development. I have 10 years of diverse experience in software development. Founder @ Studytonight