issue with brackets in jQuery Form Data when sending data as json

Question

I have the object

    var dataformdata={"key1":"value1","key2":"value2"};

then I add some more values with the same key(key3) like this

    dataformdata.key3 = [];
    dataformdata.key3.push("value3");
    dataformdata.key3.push("value4");

I do the above in an each slope. It all works except when sending the dataformdata object via the jQuery ajax function in the browser console I see that there are brackets in the key ...

$.ajax({ type: "POST", url: "/", data: dataformdata,...

This is what I see in the browser console:

key1:value1
key2:value2
key3%5B%5D:value3
key3%5B%5D:value4

It should work because in the jQuery.ajax() docs it says

Object must be Key/Value pairs. If value is an Array, jQuery serializes multiple values with same key based on the value of the traditional setting

But why are the brackets (%5B%5D) in the key?

Answer 1

you can also use the traditional settings in the ajax call http://api.jquery.com/jquery.ajax/#jQuery-ajax-settings

traditional Type: Boolean

Set this to true if you wish to use the traditional style of param serialization.

for example:

$.ajax({
 /*usual stuff */
 traditional: true
})