jsonp learn about

this pattern is called jsonp and is a way to use json to solve the problem of reading data across domains.

what is cross-domain?
for example, suppose I open a web page with the address www.1234.com , but I want to go to the www.3456.com address to get the data. If the current page address is not the same as the domain name from which the data is obtained, it is called cross-domain.

in order to solve the cross-domain problem, jsonp imitates the way of calling js (there is no cross-domain). The < script > tag is dynamically added to call the js script provided by the server, and then get the name of the calling method and the data it wraps. Of course, the jsonp solution is not limited to cross-domain situations, but it can also be used in the same domain, but it is not as convenient as the simple json method.

if the landlord is still confused, it is recommended to read this article to learn more

is artificially spelled like this, in order to solve cross-domain problems.
there is no cross-domain problem when js is introduced, and it is executed automatically after js, so the foreground defines the method, and the background dynamically generates the js, that executes this method with the data as parameters. This is called jsonp