Serializing to JSON in jQuery

Herb Caudill picture Herb Caudill · Oct 10, 2008 · Viewed 884k times · Source

I need to serialize an object to JSON. I'm using jQuery. Is there a "standard" way to do this?

My specific situation: I have an array defined as shown below:

var countries = new Array();
countries[0] = 'ga';
countries[1] = 'cd';
...

and I need to turn this into a string to pass to $.ajax() like this:

$.ajax({
    type: "POST",
    url: "Concessions.aspx/GetConcessions",
    data: "{'countries':['ga','cd']}",
...

Answer

user18015 picture user18015 · May 26, 2009

JSON-js - JSON in JavaScript.

To convert an object to a string, use JSON.stringify:

var json_text = JSON.stringify(your_object, null, 2);

To convert a JSON string to object, use JSON.parse:

var your_object = JSON.parse(json_text);

It was recently recommended by John Resig:

...PLEASE start migrating your JSON-using applications over to Crockford's json2.js. It is fully compatible with the ECMAScript 5 specification and gracefully degrades if a native (faster!) implementation exists.

In fact, I just landed a change in jQuery yesterday that utilizes the JSON.parse method if it exists, now that it has been completely specified.

I tend to trust what he says on JavaScript matters :)

All modern browsers (and many older ones which aren't ancient) support the JSON object natively. The current version of Crockford's JSON library will only define JSON.stringify and JSON.parse if they're not already defined, leaving any browser native implementation intact.