Explanation: Asynchronous JavaScript and XML. The equivalent of adding a middle tier (Ajax engine) between the user and the server, which causes the user operation to be asynchronous with the server response.
Advantages: No refresh of the page, user experience, asynchronous and server communication, front-end load balancing, standards-based is widely supported, interface and application separation.
Cons: It destroys browser mechanism, weak search engine support, AJAX security problem, and destroys program exception handling mechanism.
Application: Baidu search engine, automatically obtain the associated information, registered account exists.
Ajax can receive strings, HTML tags, CSS style content, XML content, JSON content, and so on.
Ajax operations Specific steps: 1. Create an Ajax object, 2. Create a new HTTP request, 3. Send a request, 4. Set events, perceive state changes, receive server return information.
Ajax Common Object Members: 1), member properties: ResponseText, ReadyState, onreadystatechange. 2), Member Method: Open (), send ().
Ajax request get and Post differences: 1), to the server transfer data size, 2), post transmission data is more secure than get, 3), the transmission of data in different forms.
How Ajax Works