JavaScript Introduction

Table of Contents

JavaScript was developed by Brendan Eich in 1995, and became an ECMA standard in 1997. ECMA-262 is the official name of the standard. ECMAScript is the official name of the language.

JavaScript and Java completely different from each other both in design and concepts.

Today HTML,CSS and JavaScript are very much crucial scripting languages for web developers. Let us understand their role in web development

HTML-is used to define the content of a web page.

CSS-is used to specifies layout of a web page.

JavaScript- programs the behavior of a web page.

JavaScript is a lightweight, interpreted scripting programming language. It is designed for creating network-centric applications. JavaScript is extremely easy to implement because it’s integrated with HTML. It is open and cross-platform.
JavaScript can be used in developing great front-end also as back-end software using different JavaScript based frameworks like jQuery, Node.JS etc.

JavaScript comes installed on every modern browser then to find out JavaScript you actually don’t need any special environment setup. For example Chrome, Mozilla Firefox , Safari and each browser you recognize as of today, supports JavaScript.

JavaScript is used to create really beautiful and fast websites. You can develop your website with a console like look and feel and provides your users the simplest Graphical User Experience.

JavaScript usage has now emerged in various application development environments like mobile app development, desktop app development, and game development. Due to its vast applicability, there’s plenty of job options in the market with good payout.

Great thing about JavaScript is that you simply will find plenty of frameworks and Libraries already developed which may be used directly in your software development which reduced the development time to great extent.

JavaScript code are written within <script>..</script> tags. <script> tags, can be placed anywhere in a page containing JavaScript, but it is normally recommended that you should keep it within the <head> tags.The complete syntax of script tag is as under:

<script language = "JavaScript" type = "text/JavaScript">   </script>

The script tag takes two important attributes −

Language− The Language attribute here tells about the scripting language you’re using. Typically, its value will be JavaScript. In the latest versions of HTML have eliminated its use.
Type− Type attribute tells about the scripting language in use and its value is written as “text/JavaScript”.

Nowadays we can simply write script tag ignoring its language and type attributes.

JavaScript Framework and Libraries

JavaScript frameworks are pre-written JavaScript codes of JavaScript libraries which are used in regular programming features and tasks. It’s different from a JavaScript library in its control flow: A JavaScript library contains the functions which is to be called by its parent code, on the other hand a framework is used to define the whole application design.

Currently, There are a lots of JavaScript frameworks and libraries available in the market:

Mithril

Node.js

Angular.js

React.js

jQuery

Vue.js

Ext.js

Ember.js

Meteor

Polymer

Aurelia

Backbone.js

Applications of JavaScript

JavaScript is one of the highest used programming languages. It has its strong presence in the most of the areas of software development.

Client side validation– User input should be verified before submitting it to the server, at the front end . This task can be done by JavaScript.
Manipulating HTML Pages– JavaScript manipulates HTML page on the go , by adding and deleting any HTML tag very easily using JavaScript and it also modifies HTML to change its look and feel based on various devices and demand.
User Notifications– JavaScript generates dynamic pop-ups on the web pages which serves as notifications to website visitors.
Back-end Data Loading– Ajax libraries in JavaScript provides the loading of back-end data while you are working on some other processing.
Presentations– JavaScript also facilitates in creating presentations which enhances the look and feel of a website. RevealJS and BespokeJS libraries of JavaScript is used to build a web-based slide presentations.
Server Applications– Node JS is a server side scripting language which is built on Chrome’s JavaScript runtime. It builds really fast and scalable network applications. Node.js is an event based library to develop very sophisticated server applications including Web Servers.

Advantages of JavaScript

The main advantages of using JavaScript are −

Lesser server interaction− User input can be validated before sending the page off to the server resulting lesser server traffic, which means lesserload on your server.
Faster feedback to the visitors− Users don’t have to wait for a page reload to see if they have missed to enter something.
More interactive− Users can create interfaces that responds when the user hovers over them with a mouse or activates them via the keyboard.
Rich interfaces− JavaScript include items to drag-and-drop components and sliders to give a Rich Interface to the site visitors.

Limitations of JavaScript

JavaScript is not a full-fledged programming language but a scripting Language. It lacks the following important features −

Client-side JavaScript can not read or write to files. Although This has been done for security reasons.
JavaScript does not have support libraries for networking so it cannot be used for networking applications.
JavaScript doesn’t support any multi-threading or multiprocessor features.

Hence, JavaScript is a lightweight, interpreted scripting programming language that allows to create interactive pages otherwise HTML pages are static.

JavaScript Development Tools

It is one among the most advantage of JavaScript is that it doesn’t require expensive development tools. A simple text editor like Notepad can be put into use. Also it is an interpreted language and interpreted by the web browser, so no extra compiler is needed.

Some of JavaScript editing tools are being listed here −

Microsoft FrontPage−FrontPage is an HTML editor developed by Microsoft . FrontPage has many JavaScript tools which assists in the development of interactive websites.
Macromedia Dreamweaver MX− Macromedia Dreamweaver MX is a HTML and JavaScript editor used by most of the professional web developers.
Macromedia HomeSite 5− HomeSite 5 may be a HTML and JavaScript editor from Macromedia that’s would be used to manage personal websites effectively.
Notepad++ – Notepad++ is a text and source code editor used in Microsoft Windows.

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To visit the Official website of JavaScript Click here

Where to write JavaScript Code , How to Generate Output in JavaScript

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