Web Programming| AJAX Questions and Answers

Web Programming| AJAX AJAX - Answer- Asynchronous JavaScript and XML. This is not a new programming language, but a new way to use existing standards. Definition of AJAX - Answer- Exchanging data with a server, and updating parts of a web page - without reloading the whole page True or False? AJAX is about updating parts of a web page, without reloading the whole page. - Answer- TRUE! AJAX is a technique for creating fast and dynamic web pages. True of False? AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page. - Answer- True 1st Step of: How AJAX Works - Answer- In Browser: An event occurs->Create an XMLHttpRequest Object ->Send HttpRequest [[Goes to Internet]] 2nd Step of: How AJAX Works - Answer- In Server: -> Process HTTPRequest ->Create a Response and send data back to browser [[Back to Internet]] 3rd Step of: How AJAX Works - Answer- Back In Browser: -> Process the returned data using JavaScript --> Update page content AJAX is based on internet standards, and uses a combination of: - Answer- - XMLHttpRequest object (to exchange data asynchronously with a server) - JavaScript/DOM (to display/interact with the information) - CSS (to style the data) - XML (often used as the format for transferring data) True of False? The keystone of AJAX is the XMLHttpRequest object - Answer- True True of False:: All modern browsers support the XMLHttpRequest object - Answer- True. All modern browsers have a built-in XMLHttpRequest object. Old versions of Internet Explorer (IE5 and IE6) uses an ActiveX Object. To handle all modern browsers, including IE5 and IE6, check if the browser supports the XMLHttpRequest object. If it does, create an XMLHttpRequest object, if not, create an ActiveXObject: How to send a request to server? - Answer- To send a request to a server, we use the open() and send() methods of the XMLHttpRequest object GET is simpler and faster than POST, and can be used in most cases. However, always use POST requests when: - Answer- A cached file is not an option (update a file or database on the server) Sending a large amount of data to the server (POST has no size limitations