Introduction to JavaScript

Limitation of Plain HTML and requirement of a scripting :

The web pages which were Created in plain HTML were relatively plain and simple. There was no mechanism in plain HTML code to perform any or display any special effects based on user interaction. When this requirement was realized, developers began to think about introducing scripting languages that could be used, understood and executed by Web browser along with HTML. It was to overcome these issues that JavaScript was developed as one of the scripting languages.

Introduction :

JavaScript is an object oriented scripting language used in web pages to perform task such as validation of data, processing of numbers and notification of form contents. It is an interpreted language meaning that it's code is executed without preliminary complilation. JavaScript is executed by compatible Web browser. Almost all popular current web browser execute JavaScript. It can be embedded in web pages or can be written in separate files as well. JavaScript was formerly developed by Brendan Eich from Netscape Communication in early 1996 Java and JavaScript are two completely different languages. Java developed by Sun Microsystems is a powerful and complex programming language. JavaScript was first supported by Netscape's Navigator Browser Very. 2 in early 1996.

Features of JavaScript :

1. JavaScript is the only scripting language supported by all Web Browser. In comparison to JavaScript, Microsoft's VB Script only supported by Microsoft's Internet Explorer Browser within the windows OS. JavaScript is therefore referred to as the Universal scripting language.
2. JavaScript is mad up of executable computer code. When JavaScript is included in an HTML web page, the script is interpreted and executed by the Web Browser (client) along with the HTML code.
3. JavaScript can be embedded directly in HTML pages or could be used from a separate file.
4. Everyone can use JavaScript without purchasing a license. JavaScript is the most popular scripting language on the internet and is used in millions of Web pages to improve the design, validate forms, and much more.
5. JavaScript is case sensitive, therefore any variable or function named as "ABC" is not same as "abc".

In next Post we will learn about Client Side Scripting & Server Side Scripting.