How to add additional key and the value to json array

Question

I am getting my form data in to a array with

var fields = $(this).serializeArray();

I want to push the dynamic token value to this array before I make ajax call to process this array in php.

I try with

fields.push({token:value});

my ajax call to php is

$.ajax({

    type : 'POST',
    url : "test.php",
    data : fields,
    dataType : 'json',
    success: function(data) {......},
    error{....}
});

In my test.php page I want to use that token value like

 $token = $_POST[token];

but the $token value is null.

possible duplicate of [Can I add data to an already serialized array?](http://stackoverflow.com/questions/14102732/can-i-add-data-to-an-already-serialized-array) — Felix Kling, Jun 03 '13 at 20:32
You could have a look at the `serializeArray` function and how the array is structured: http://api.jquery.com/serializeArray/. — Felix Kling, Jun 03 '13 at 20:33

score 2 · Accepted Answer · edited May 23 '17 at 11:57

.serializeArray returns an array with the structure

[{name: 'name', value: 'value'}, ...]

So you have to add an object with name and value properties:

fields.push({name: 'token', value: 'value'});

Or if token and value are variables:

fields.push({name: token, value: value});

Have a look at the documentation for more information.

I have already answered that in another question: Can I add data to an already serialized array?.

score 1 · Answer 2 · answered Jun 03 '13 at 20:32

1

Try this:

fields[token] = value;

If you use push, you're just pushing a value onto the end of the array, and the last index will just increment.

answered Jun 03 '13 at 20:32

Richard

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If it would have been an object it would be `fields.token = value;`. It is correct – Richard Jun 03 '13 at 20:34
No! Whether you use dot notation or bracket notation does not matter. I assume `token` contains a string... do you use string keys with arrays? I hope not. – Felix Kling Jun 03 '13 at 20:34
If I use this ajax call fails. – VDN Jun 03 '13 at 20:35
Why assume `token` is a string? `fields` is an array regardless... Token could be anything. – Richard Jun 03 '13 at 20:37
I don't assume anything. Topic poster is using an array and wants an item added onto it, apparently with a unique identifier. – Richard Jun 03 '13 at 20:38
You can add elements to the array this way **if and only if** `token` is a number. But the problem is that `fields` is an array with a very **specific** structure and it has to have this structure if you want to make it work with `$.ajax`. Doing `fields[token] = value;` does not keep the structure. See my answer. – Felix Kling Jun 03 '13 at 20:40
@FelixKling that's blatantly wrong. arrays ARE objects in javascript, and you can add properties to arrays just like you'd add them to any other object. – user428517 Jun 03 '13 at 20:44
@sgroves: I never said arrays are not objects (well ok, I wanted to point out that `fields` should be treated as array and not as plain object). You shouldn't add properties with non-numeric names to it like this. They will all be ignored by array methods. And in any case, even if `token` was a numeric value, it wouldn't help the OP. The array has a specific structure as I already said a couple of times. – Felix Kling Jun 03 '13 at 20:45

How to add additional key and the value to json array

2 Answers2