Sending an empty array from ajax gave a null parameter in ASP.NET MVC action

Question

I have a simple ajax call like:

$.ajax({
   url: ... ,
   data: { anArray: [] },
   ...
});

and the controller's action:

public ActionResult Test(int[] anArray) {
   ...
}

seems that anArray is null instead of empty array.

I tried also with

but for all of above, I see null for anArray parameter.

I read similar questions but there are related to model parameters, I don't have, here, model.

How to receive an empty array in controller's action ? What should I do ?

have you add dataType to your ajax call?Your data does't reach to action method — Suren Srapyan, Nov 13 '15 at 09:20
i want to see if correct content type is set like, `contentType:"application/json"`. — Jai, Nov 13 '15 at 09:21
Is it a post or get? I've found with C#'s MVC I typically need to put `dataType: 'json'` as well as @Jai's suggestion. Further, you should be able to simply do `data: []`. — Rob, Nov 13 '15 at 09:33

score 3 · Answer 1 · answered Nov 13 '15 at 09:54

It seems that MVC maps empty arrays to a null; this is by design for some reason. I guess you can't do much with an array of zero items anyway.

It seems that your best bet is to instantiate the array yourself if it does come through as null:

        public ActionResult Test(int[] anArray)
        {
            anArray = anArray ?? new int[0];

            //...
        }

1 Answers1