What is Javascript ?
JAVASCRIPT is now considered as the most popular software programming language in the world. JavaScript was originally developed by Brendan Eich and first appeared in beta releases of Netscape Navigator 2.0 in September 1995. Its main purpose was to create interactive web pages and handle basic form validation that had been previously done with server-side technologies such as CGI, Perl etc. The main reason for choosing JavaScript is its compatibility and availability.
Three Layers of Web Development
HTML defines the structure and layout of a Web document by using a variety of tags and attributes. Since its initial introduction in late 1991, it came to encompass a wider variety of stylistic and dynamic behavior capabilities to meet the demands of web developers. When we examine the elements of a web page, we can find that, it can consist of up to three layers.
1. Content or Structure
2. Style or Presentation
3. Behavior
Content or Structure is the base layer, we presented it through HTML (Hyper Text Markup Language) format and it describes text, graphics, and files containing other information are organized and linked together. For Style or Presentation, we can focus on making the site look attractive, by adding a layer of presentation information using CSS (Cascading Style Sheet). Finally for Behavior, we can use JavaScript to introduce an added layer of user interaction and dynamic behavior, which will make the site easier to use in browsers equipped with JavaScript.
Difference between JavaScript and Java
There are a lot of people believe that JavaScript is a sort of simplified version of Java. Although JavaScript has a similar syntax and programming methodology, actually it has nothing to do with the Java programming language. Java is an OOP programming language ,while Java Script is an OOP scripting language. Java develops applications that run in a virtual machine environment or browser while JavaScript code is run only in a browser environment. Finally, Java is compiled prior to runtime while Javascript are read and executed by an interpreter at runtime.
JavaScript is not the only scripting language; there are other scripting languages such as Perl, VBScript etc. JavaScript is recognized as a full programming language, capable of complex calculations and interactions… from the following lessons you can study this language in detail.