FEATURES OF JAVASCRIPT

In this tutorial, we are going to learn about the features of javascript. When it comes to web development, avaScript is one of the most popular languages with a variety of capabilities. According to Github, it's one of the most used programming languages, and we need to comprehend the features of JavaScript in order to fully appreciate what it can do.

Table of Contents

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  • Features of Javscript
  • Limitations of JavaScript
  • Recommended Articles

Features of JavaScript

Limitations of JavaScript

Main Feature of JavaScript are :

  • 1. Light Weight Scripting language.
  • 2. Platform Independent
  • 3. Verifying the User's Input
  • 4. Asynchronous Processing
  • 5. Detecting the User’s Browser and OS
  • 6. JavaScript is a object-based scripting language.
  • 7. Handling Events
  • 7. Case Sensitive Language

JavaScript is a Light Weight Scripting language

Because it is designed solely for data handling in the browser,JavaScript is a lightweight scripting language. It has a limited number of libraries because it is not a general-purpose language. The lightweight nature of JavaScript is also a beneficial attribute because it is exclusively meant for client-side execution and that too for web apps.

Why JavaScript is called as Lightweight Programming Language ?

Because it can have programming functions but not do tougher operations like Java and C++, JS is known as the "Lightweight Programming Language."

Is the interpreter/compiler/execution environment for that language simple and fast? This is a related method to think about whether a language is lightweight. This is only achievable if the language is straightforward. In the last few years, JavaScript engines have become a lot more complicated, but the tradeoff is that running JavaScript code has become a LOT faster.

Platform Independent

Because JavaScript is interpreted by browsers, it eliminates the need for compilation and compatibility. As a result, it runs on Windows, Macintosh, and other Netscape-compatible platforms. It's also possible to incorporate them in any other script that uses JavaScript, such as HTML.

This means that JavaScript is Platform Independent or portable, which basically means that you can write the script once and run it everywhere and at any time. In principle, JavaScript programmes can be written and run on any platform or browser without changing the script's output.

To run JavaScripts, different browsers use different engines, such as Chrome's V8, Firefox's SpiderMonkey, and Edge's Chakra. In principle, JavaScript programmes can be written and run on any platform or browser without changing the script's output. Any JavaScript code is run on the various types of hardware for which it was designed.

Any browser that supports JavaScript can comprehend and interpret JavaScript code, which means you can write the script once and run it anywhere, at any time.

As a result, we can refer to it as a platform-independent or portable application.

Verifying the User's Input

When working with forms, JavaScript comes in handy. Javascript provides the ability to check for errors in the user's input while also saving time. Before transmitting the data to the server, JavaScript checks to see if the user has left a mandatory field blank or if you have entered inaccurate information.

Asynchronous Processing

JavaScript has Promise, which allows for asynchronous requests in which a request is made and JavaScript does not have to wait for the response, which might sometimes cause the request to be blocked.

Asynchronous functions are also allowed in JavaScript starting with ES8. These functions do not execute one by one, but rather in parallel, which has a good effect on processing time, decreasing it significantly.

Things can happen independently of the main program flow if they are asynchronous.

The mechanism employed in JavaScript is an event loop, which processes a callback queue in order from oldest to newest items. Each message in the queue is processed entirely before going on to the next message in the queue. Each message is a function that responds to code in another part of the programme. Callback functions are functions that are utilised in this fashion.

Because of callbacks, JavaScript may employ a variety of strategies to accomplish asynchronous processing despite its single-threaded nature. Unfortunately, several of those solutions, such as JavaScript Promises and RxJS Observables, require you to write code with at least one nested level. The code becomes less readable and manageable as a result.

Fortunately, newer versions of JavaScript include an async and await method for working with asynchronous programming. It's ideal for when you want your application to synchronously halt while performing an asynchronous operation, then resume work after the action is completed.

We would learn more about async/ await and callbacks in the later tutorials

Detecting the User’s Browser and OS

JavaScript is quite good at detecting the user's browser and operating system. Despite the fact that JavaScript runs on all platforms, there may be times when we need the user's browser before proceeding. This can be useful when writing code that produces different outputs depending on the browser.

Using plain JavaScript, you can determine which browser the user is using. To determine the user browser, look at the object navigator's userAgent attribute.If you wish to perform something particular, like as create a polifill for a regular expression in Safari, follow these steps:

if (navigator.userAgent.includes('Safari'))
{
     // the user is running Safari
     // do something useful
 }

JavaScript is a object-based scripting language

JavaScript is a computer language that is based on prototypes(probably prototype-based scripting language is more correct definition). It makes use of cloning rather than inheritance. A prototype-based programming language is an object-oriented programming paradigm that does not use classes.

Object-oriented programming languages encourage developers to concentrate on taxonomy and relationships, whereas prototype-based programming languages encourage developers to concentrate on behaviour first and then classify later.

Unlike most object-oriented languages, JavaScript (at least before ECMA 262 Edition 4) includes prototypes rather than classes. As a result, deciding whether to call it object-oriented or not is somewhat subjective.

Handling Events

When an event happens, you can write an event handler, which is a piece of code that runs in response to the event. The term "event handler" is also used to refer to an event listener. It listens to the event and reacts appropriately when it occurs.

An event listener is a resuable function with an explicit name, or an anonymous function if it is only called once.

One or more event handlers can respond to an event. When an event with multiple event handlers is fired, all of the event handlers are executed.

There are three ways to assign event handlers.

  • 1. HTML event handler attributes.
  • 2. DOM Level 0 event handlers - onclick()
  • 3. DOM Level 2 event handlers - addEventListener(), removeEventListener()

We would learn more about each of them in detail in the upcoming tutorials

Case Sensitive Language

The language JavaScript is case-sensitive. This means that all language keywords, variables, function names, and other identifiers must be entered with the same capitalization. For example, the while keyword must be typed "while," not "While" or "WHILE." Online, Online, OnLine, and ONLINE are also four different variable names.

Case sensitivity applies not only to variable names in JavaScript, but also to JavaScript keywords, event handlers, and object properties and functions. JavaScript keywords are all lowercase, such as while, for, if, else, and so on. Methods (properties) on the other hand, such as toArray() and lastModified(), employ a"camel-back" naming pattern (the first word is in lowercase and each subsequent initial letter of each word is capitalised).

HTML, on the other hand, is not case-sensitive. This distinction can be confusing due to its strong interaction with client-side JavaScript. The names of many JavaScript objects and properties are the same as the names of the HTML tags and attributes that they represent.

While these tags and attribute names can be put in any case in HTML, they must all be lowercase in JavaScript. The HTML onclick event handler attribute, for example, is typically supplied as onClick in HTML, but in JavaScript code, it must be referred to as onclick.

Limitations of JavaScript

Client-side File reading and writing are not supported by JavaScript.

Because no networking functionality is available, it can't be used for networking applications.

It lacks multithreading and multiprocessing capabilities.

Recommended Articles

This was a tutorial on JavaScript's Features. Here we have discussed the benefits and drawbacks of using JavaScript.You can also go through our other suggested articles to learn more –