Ajax synchronous, asynchronous

Transferring data

Synchronization: The first pass the past, the other party received feedback, and then pass the second article;

Async: The first pass, whether or not the other party has received, continue to pass the second article.

Ajax (default async async:true)

Synchronization: After executing AJAX internal code, execute the following code;

Async: Executes the AJAX internal code while continuing to execute the following code, both synchronously.

In contrast, the asynchronous operation is efficient, but the following may not receive the passed value, because it is not certain that Ajax internal code is executed.

Ajax synchronous, asynchronous