How to understand the essence of Ajax

Today, I will talk to you about how to understand the essence of Ajax. Many people may not understand it. In order to let everyone know more, Xiaobian summarizes the following contents for everyone. I hope everyone can gain something according to this article.

1、Ajax (Asynchronous JavaScript and XML）

Ajax definition: technology that allows client browsers to communicate with servers without refreshing the current page is ajax technology.

2, do not refresh the page, and the server communication technology is ajax, flash, javaApplet, framework (iframe, frameset), XMLHttpRequest.

Note: the frame is to put multiple pages in the frame, is a cross-page operation, and the real page does not refresh, and server communication is different. Only refresh the pages in a frame, the whole page is not refreshed.

The core of Ajax is the JavaScript object XMLHttpRequest.

Ajax is not a new technology, it is a synthesis of many technologies, including JavaScript, XHTML,CSS,DOM,XML,XMLHttpRequest.

5. Ajax implementation steps:

1) Create XMLHttpRequest object

2) Establishing a connection

3) Send request data to server

4) Server responds to client

There are also two if judgments, to determine whether readyState is equal to 4, that is, the response is complete, whether status is equal to 200., Everything is normal.

Having read all this, do you have any idea what Ajax is all about? If you still want to know more knowledge or related content, please pay attention to the industry information channel, thank you for your support.