Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

JavaScript: Implementations And Applications

430 views

Published on

This is a presentation on the basics of JavaScript and gives you some basic knowledge about this language.

Published in: Technology
  • Be the first to comment

  • Be the first to like this

JavaScript: Implementations And Applications

  1. 1. JAVASCRIPT: IMPLEMENTATIONS AND APPLICATIONS
  2. 2. What is JavaScript?  JavaScript is a front-end scripting language developed by Netscape for dynamic content.  It is a programming language that makes a website interactive  It is lightweight and can be used as an Object Oriented Language
  3. 3. How Was JavaScript Created?  It was first created by Brendan Eich at Netscape in 1995  It was named Mocha during development and released in beta as LiveScript  Ultimately named JavaScript to piggyback on the popularity of Java for marketing reasons
  4. 4. JavaScript VS Java JavaScript Java Interpreted (not compiled) by client. Compiled byte codes downloaded from server, executed on client. Object-oriented. No distinction between types of objects. Inheritance is through the prototype mechanism, and properties and methods can be added to any object dynamically. Class-based. Objects are divided into classes and instances with all inheritance through the class hierarchy. Classes and instances cannot have properties or methods added dynamically. Code integrated with, and embedded in, HTML. Applets distinct from HTML (accessed from HTML pages Variable data types not declared (dynamic typing). Variable data types must be declared (static typing). Cannot automatically write to hard disk. Cannot automatically write to hard disk
  5. 5. When is JavaScript Executed?  JavaScript code is Executed during the page loading or when the browser fires an event  All statements are executed at page loading  Some statements define functions that can be called later
  6. 6. Why JavaScript is Widely Used?  JavaScript is the only client-side scripting language  It runs in a browser so you don’t need to download any software to use it  A web page can be used without a JavaScript but using JavaScript improves a visitor’s experience
  7. 7. Some Advantages Of JavaScript JavaScript allows interactivity such as:  Implementing form validation  Content loading and changing dynamically  Implementing AJAX functionality
  8. 8. Some Advantages of JavaScript  Can read and write HTML element and modify the DOM structure  Can handle exceptions
  9. 9. Using The JavaScript Code  The JavaScript code can be placed in the <script> tag in the head <script> tag in the body  There are two types of files used with the JavaScript language:
  10. 10. 1) Including it’s code in any other file for example an HTML file or in any other script or non script-based file 2) The file in this case would have the extension appropriate to the type of file for example .htm or .html for an HTML file. 3) Another way is to create a file that uniquely contains JavaScript code with .js extension
  11. 11. Writing the First JavaScript <html> <body> <head> <script type="text/javascript"> document.write('Hello JavaScript!'); </script> </head> </body> </html>
  12. 12. THE DOCUMENT OBJECT MODEL(DOM)
  13. 13.  The way that document content is accessed and modified is called the Document Object Model, or DOM. The Objects are organized in a hierarchy. This hierarchical structure applies to the organization of objects in a Web document.  Window object: Top of the hierarchy. It is the outmost element of the object hierarchy.
  14. 14.  Document object: Each HTML document that gets loaded into a window becomes a document object. The document contains the content of the page.  Form object: Everything enclosed in the <form>...</form> tags sets the form object.  Form control elements: The form object contains all the elements defined for that object such as text fields, buttons, radio buttons, and checkboxes.
  15. 15. Implementation Of JavaScript  Rhino is an open-source implementation of JavaScript written entirely in java.  It is typically embedded into java applications to provide scripting to end users.
  16. 16. Conclusion  JavaScript is a programming language that is widely used and will become more popular in the future with the advancement of technology.  It is also used an Object Oriented Language
  17. 17. Sources -> W3Schools.com-some tutorials on the basics of JavaScript -> SlideShare.net- implementing ideas -> tutorialpoint.com -> quora.com

×