Why jQuery consider an 200 response Ajax request with empty content as fail()?

Question

First, there\'s no cross-region problem at all.

I found if the server response an empty content body, jQuery consider this as fail()?

Why is this?

Answer 1

If you're using jQuery >= 1.9 an empty JSON response will be rejected, according to the API documentation:

The JSON data is parsed in a strict manner; any malformed JSON is rejected and a parse error is thrown. As of jQuery 1.9, an empty response is also rejected; the server should return a response of null or {} instead.