Post: Generally used to submit the form, the request data is wrapped in the body, which is safe;
Get: Generally used to obtain the data information, of course, it can also be used to obtain the form, the request parameter is in the url, which is not safe;
Content-Type
contype-Type is used to specify the request information of upload parameters in different formats;
content-Type commonly used data types:
1. application/json, use it as the request header to tell the server that the message body is a serialized JSON string.
2. application/x-www-form-urlencoded, the default data format of the form, the submitted data is encoded according to key1=val1&key2=val2, and both key and val are URL transcoded. (Ajax default Content-Type type)
responseType
responseType is used to specify the type of response data returned by the background.