Parse JSON in JavaScript? [duplicate]

First of all, you have to make sure that the JSON code is valid.

After that, I would recommend using a JavaScript library such as jQuery or Prototype if you can because these things are handled well in those libraries.

On the other hand, if you don't want to use a library and you can vouch for the validity of the JSON object, I would simply wrap the string in an anonymous function and use the eval function.

This is not recommended if you are getting the JSON object from another source that isn't absolutely trusted because the eval function allows for renegade code if you will.

Here is an example of using the eval function:

var strJSON = '{"result":true,"count":1}';
var objJSON = eval("(function(){return " + strJSON + ";})()");
alert(objJSON.result);
alert(objJSON.count);

If you control what browser is being used or you are not worried people with an older browser, you can always use the JSON.parse method.

This is really the ideal solution for the future.

If you are getting this from an outside site it might be helpful to use jquery's getJSON. If it's a list you can iterate through it with $.each

$.getJSON(url, function (json) {
    alert(json.result);
    $.each(json.list, function (i, fb) {
        alert(fb.result);
    });
});

If you want to use JSON 3 for older browsers, you can load it conditionally with:

<script>
    window.JSON || 
    document.write('<script src="//cdnjs.cloudflare.com/ajax/libs/json3/3.2.4/json3.min.js"><\/scr'+'ipt>');
</script>

Now the standard window.JSON object is available to you no matter what browser a client is running.

The following example will make it clear:

var jsontext   = '{"name":"x","age":"11"}';
var getContact = JSON.parse(jsontext);
document.write(getContact.name + ", " + getContact.age);

// Output: x, 11

OR

You can also use the eval function. The following example is using the eval function:

var jsontext   = '{"name":"x","age":"11"}';
var getContact = eval('(' + jsontext + ')');
document.write(getContact.name + ", " + getContact.age);

// Output: x, 11

Since the JSON.parse function is more secure and executes faster than the eval function, I recommend you to use JSON.parse function.

You can either use the eval function as in some other answers. (Don't forget the extra braces.) You will know why when you dig deeper), or simply use the jQuery function parseJSON:

var response = '{"result":true , "count":1}'; 
var parsedJSON = $.parseJSON(response);

OR

You can use this below code.

var response = '{"result":true , "count":1}';
var jsonObject = JSON.parse(response);

And you can access the fields using jsonObject.result and jsonObject.count.

If you pass a string variable (a well-formed jsonstring) 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, '"');  

The easiest way using parse() method:

var response = '{"a":true,"b":1}';
var JsonObject= JSON.parse(response);

this is an example of how to get values:

var myResponseResult = JsonObject.a;
var myResponseCount = JsonObject.b;

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

For Better understanding press F12 to open Inspect Element of your browser and go to console to write following commands : -

var response = '{"result":true,"count":1}'; //sample json object(string form)
JSON.parse(response); //converts passed string to 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 dot(.) operator you can access properties of the JSON Object.

Try to run the command

console.log(obj.result);

Without using a library you can use eval - the only time you should use. It's safer to use a library though.

eg...

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

var parsedJSON = eval('('+response+')');

var result=parsedJSON.result;
var count=parsedJSON.count;

alert('result:'+result+' count:'+count);

If you like this :

var response = '{"result":true,"count":1}';
var JsonObject= JSON.parse(response);

you can access the JSON elements by JsonObject with (.) dot

JsonObject.result;
JsonObject.count;

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.

an easy way to do it

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

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)

Just wanted to add the stuff about angularjs to provide another option. NOTE that angularjs doesn't officially support IE8 (and older versions, for that matter), though through experience most of the stuff seems to work pretty well.

if you use dojo

http://dojotoolkit.org/reference-guide/1.10/dojo/json.html

require(["dojo/json"], function(JSON){
  JSON.parse('{"hello":"world"}', true);
});

If you use jQuery, it is simple:

var response = '{"result":true,"count":1}';
var obj = $.parseJSON(response);
alert(obj.result); //true
alert(obj.count); //1