New to JSON, what can I do with this json response

Question

Hi,

A website returns the following JSON response, how would I consume it (in javascript)?

[{"ID1":9996,"ID2":22}]

Is JSON simply returning an array?

Answer 1

We use:

function evalResponse(response) {
    var xyz123 = null;
    eval("xyz123 = " + response);
    return xyz123;
}

An alternative method is to simply use:

var myObj = eval(response);

Basically, you have to call eval() on the response to create a javascript object. This is because the response itself is just a string when you get it back from your AJAX call. After you eval it, you have an object that you can manipulate.

function myCallback(response) {
    var myObj = evalResponse(response);
    alert(myObj.ID1);
}

You could use a javascript library to handle this for you. Or, you could try to parse the string yourself. eval() has it's own problems, but it works.

Answer 2

Here's how you get to your data:

<script type="text/javascript" >
var something = [{"ID1":9996,"ID2":22}]
alert(something[0].ID1)
</script>

Answer 3

It looks like an array with a single object holding two properties. I'd much prefer to see the same data structured like this:

{"ID":[9996,22]}

Then you have a single object holding an array with two elements, which seems to be a better fit for the data presented. Then using Endangered's evalResponse() code you could use it like this:

var responseObj = evalResponse(response);

// responseObj.ID[0] would be 9996, responseObj.ID[1] would be 22

Answer 4

The JSON you posted represents an array containing one object, which has attributes ID1 and ID2 (initialized to the respective values after the colon).

To convert the string to a javascript object, pass it to eval, like this:

var obj = eval('[{"ID1":9996,"ID2":22}]');

However, this method will fail if you only have a single object instead of an array, so it is safer to wrap it in parenthesis:

var obj = eval('(' + jsonResponse + ')');

Answer 5

If you use http://www.JSON.org/json2.js you can use it's method JSON.parse to retrieve the json string as an object (without the use of eval (which is considered evil)), so in this case you would use:

var nwObj = JSON.parse('[{"ID1":9996,"ID2":22}]');
alert(nwObj.ID1); //=> 9996

Answer 6

I think the other answers might not answer your question, maybe you're looking for a way to use that "array of 1 object". Maybe this can help:

var arr = [{"ID1":9996,"ID2":22}];
var obj = arr[0];
var id1 = obj.ID1;
var id2 = obj.ID2;