Parse JSON in JavaScript? [duplicate]

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Safely turning a JSON string into an object (26 answers)

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I want to parse a JSON string in JavaScript. The response is something like

var response = '{"result":true,"count":1}';

How can I get the values result and count from this?

Answer 1

The standard way to parse JSON in JavaScript is JSON.parse()

The JSON API was introduced with ES5 (2011) and has since been implemented in >99% of browsers by market share, and Node.js. Its usage is simple:

const json = '{ "fruit": "pineapple", "fingers": 10 }';
const obj = JSON.parse(json);
console.log(obj.fruit, obj.fingers);

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The only time you won't be able to use JSON.parse() is if you are programming for an ancient browser, such as IE 7 (2006), IE 6 (2001), Firefox 3 (2008), Safari 3.x (2009), etc. Alternatively, you may be in an esoteric JavaScript environment that doesn't include the standard APIs. In these cases, use json2.js, the reference implementation of JSON written by Douglas Crockford, the inventor of JSON. That library will provide an implementation of JSON.parse().

When processing extremely large JSON files, JSON.parse() may choke because of its synchronous nature and design. To resolve this, the JSON website recommends third-party libraries such as Oboe.js and clarinet, which provide streaming JSON parsing.

jQuery once had a $.parseJSON() function, but it was deprecated with jQuery 3.0. In any case, for a long time it was nothing more than a wrapper around JSON.parse().

Answer 2

JSON.parse() converts any JSON String passed into the function, to a JSON object.

For better understanding, press F12 to open the Inspect Element of your browser, and go to the console to write the following commands:

var response = '{"result":true,"count":1}'; // Sample JSON object (string form)
JSON.parse(response); // Converts passed string to a JSON object.

Now run the command:

console.log(JSON.parse(response));

You'll get output as Object {result: true, count: 1}.

In order to use that object, you can assign it to the variable, let's say obj:

var obj = JSON.parse(response);

Now by using obj and the dot(.) operator you can access properties of the JSON Object.

Try to run the command

console.log(obj.result);

Answer 3

If you pass a string variable (a well-formed JSON string) to JSON.parse from MVC @Viewbag that has doublequote, '"', as quotes, you need to process it before JSON.parse (jsonstring)

    var jsonstring = '@ViewBag.jsonstring';
    jsonstring = jsonstring.replace(/"/g, '"');  

Answer 4

As mentioned by numerous others, most browsers support JSON.parse and JSON.stringify.

Now, I'd also like to add that if you are using AngularJS (which I highly recommend), then it also provides the functionality that you require:

var myJson = '{"result": true, "count": 1}';
var obj = angular.fromJson(myJson);//equivalent to JSON.parse(myJson)
var backToJson = angular.toJson(obj);//equivalent to JSON.stringify(obj)

I just wanted to add the stuff about AngularJS to provide another option. NOTE that AngularJS doesn't officially support Internet Explorer 8 (and older versions, for that matter), though through experience most of the stuff seems to work pretty well.

Answer 5

An easy way to do it:

var data = '{"result":true,"count":1}';
var json = eval("[" +data+ "]")[0]; // ;)

Answer 6

I thought JSON.parse(myObject) would work. But depending on the browsers, it might be worth using eval('('+myObject+')'). The only issue I can recommend watching out for is the multi-level list in JSON.