How can I interpret a JSON object received as a string correctly?

Question

Hi,

I've got a broken web service that I can't access and alter. It sends down some mainly nice JSON, but one of the attributes is a nested JSON object that is being sent down as a string.

http://www.ireland.com/api/getitemweb/185213
CustomJsonData in the response from the above url is the example.

My question is how could I interpret the CustomJsonData string as an object?

I thought the 'evil' eval() might do it, but no luck.

Thanks, Denis

Answer 1

Use Douglas Crockford's implementation: http://www.json.org/json2.js

Example:

var obj = JSON.parse(aJsonString);

It handles nested arrays, objects, etc.

Answer 2

If you are using eval, you need to add a ( and ) to the string before eval:

var parsedObject = eval("(" + jsonString + ")");

However, as you said, eval is evil, using parseJson from jquery is better (and extra parens not required):

var parsedObject = Jquery.parseJSON(jsonString);

Documentation for Jquery parseJSON: http://api.jquery.com/jQuery.parseJSON/

Answer 3

You have to parse the data twice -- once to parse the entire API JSON string and once to parse the custom JSON string.

function parseJSON(data) {
    return JSON ? JSON.parse(data) : eval('(' + data + ')');
}

var data = parseJSON(apiStr);
var custom = parseJSON(data.CustomJsonData);