javascript - How to get response header information in js

Question

How to get response header information in js, use sessionstatus=XMLHttpRequest.getResponseHeader("sessionStatus"); and the result is null.

Please help me guys find out how to solve it. The screenshots are as follows:

Answer 1

var req = new XMLHttpRequest();
req.open('GET', document.location, false);
req.send(null);
var headers = req.getAllResponseHeaders().toLowerCase();
alert(headers);

Answer 2

See if you write sessionStatus in all lower case, try writing it in camel case.