Response status code
+ a number to indicate the response status of this request
=> success: successful creation, successful deletion,…
=> failure: client failure, server failure,…
+ is 100 ~ 599, divided into five categories
=> 100 ~ 199: means the connection continues
=> 200 ~ 299: means success in various senses
=> 300 ~ 399: means redirection
=> 400 ~ 499: means client error
=> 500 ~ 599: means server error
Common status code
+ 101 means the connection continues
+ 200 general success
+ 302 temporary redirect
=> this request temporarily uses the server to determine the page that the browser jumps to
+ 301 permanent redirect
=> as long as you visit this address for life, you will be re-directed Switch to the new address
+ 304 cache
=> when you visit this page once
=> the browser will automatically cache
=> when you visit the same address, it will not send a request like the server, but from the cache Get inside
+ 403 Insufficient access rights
+ 404 Access address does not exist
+ 500 General server error
+ 501 Maintenance or overload