Advance request
The figure above shows the whole process of a request, and then we can see that one of the problems we often see is the pre-request of option, so the figure does not explain what is a simple request, so the link below is to explain what is a simple request, that is, the standard of a simple request.
Standards for simple requests
After reading the article, you may understand that simple requests can be interpreted as requests without custom headers. Although it is superficial, let’s take it this way. This can simply explain why some requests need to be pre-requested and some don’t.
Because this article is to look at the others’ figure and his baidu’s standard, so I didn’t dare to write is original, after all, only the knowledge together, thanks to provide the artwork, not careless of me to his address error, but this simple request standard is can have the original link, like can go and see, write very well. Thanks to the programmers who contributed and shared their knowledge along the way.
Like my article can pay attention to, learn from each other, progress together.