Why typeof getResponseHeader is object even if null?

Asked Nov 05 '15 at 01:37

Active Nov 05 '15 at 01:37

Viewed 66 times

I am trying to check if getResponseHeader('X-CUSTOM-DATA') is set but it always return object when I do type check.

(function($) {
    $(document).ajaxComplete(function(event, response, settings) {
      
      var data = response.getResponseHeader('X-CUSTOM-DATA');
      console.log(data); // Return null.
      console.log(typeof data) // return object
      
    });
})(jQuery);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.2.3/jquery.min.js"></script>

Is this usual? How do I check if X-CUSTOM-DATA is set?

asked Nov 05 '15 at 01:37

user5284281

1

Just check if it's `null`? – gre_gor Nov 05 '15 at 01:42
I don't see why `data === null` would not suffice. [`null` is what jQuery returns if no match](https://github.com/jquery/jquery/blob/70605c8e5655da996ebd395e3c43423daaa08d9c/src/ajax.js#L458). – Alexander O'Mara Nov 05 '15 at 01:43
Thanks, data === null solved it. I thought, like mysql I cannot check null with null. – user5284281 Nov 05 '15 at 01:48

Why typeof getResponseHeader is object even if null?

0 Answers0