jQuery getJSON（） - 调用什么服务器？

Question

When using PHP I can use file_get_contents or cURL to get a URL.

jQuery runs on the client

In jQuery there is a function called jQuery.getJSON(). Javascript is run on the client. What server is used for the download of the JSON code of the external URL? What information does the called URL know about? Does it know of the domain? The IP of the client user? It's a client language.

Prefered for many request

To make many requests, is it safer to do this with Javascript than PHP because it runs on the every client instead of one server point?

Answer 1

What server is used for the download of the JSON code of the external URL?

The one that the domain name in the URL passed to that function resolves to.

What information does the called URL know about?

It is an HTTP request, like any other. The usual information will be available.

Does it know of the domain? The IP of the client user?

Of course.

It's a client language.

… making an HTTP request.

To make many requests, is it safer to do this with Javascript than PHP because it runs on the every client instead of one server point?

You control the server. You don't control the client. JavaScript can be disabled. It is safer to make the request from your server.

(For a value of "safe" equal to "Less likely to fail assuming the service you are using doesn't impose rate limiting")