How to read a json object in js

Question

My controller has a method that is returning string representation of a jsonArray as

jsonArray.toString()

Now following is the ajax method

function loadPropertyFile(url) {
$.ajax({
 type: "GET",
 url: url, 
 dataType: "text",
 success: function(response){
 var obj = jQuery.parseJSON(response);
 alert(obj);
 }
});

}

Here the variable obj after parsing comes out to be

"[{"portal.home":"Home"},{"displaytag.tracking.id":"Item ID"},{"displaytag.tracking.itemName":"Item Name"},{"displaytag.tracking.itemType":"Type"}]"

Now I want to access the values from the keys in js

ie. I want to access the value of key "displaytag.tracking.id"

Problem is when I am doing console.log(obj[0]["portal.home"]); It is giving me error TypeError: obj[0] is undefined

What shall I do ?

• adeneo: Is it a string, or do you have an actual javascript object. And this should be trivial to figure out either way ?
• César García Tapia: Trivial question, and not clearly formed.
• Bhuvan: Question edited. Please see
• YogeshWaran: Your json string should be like this '[{"portal.home":"Home"},{"displaytag.tracking.id":"Item ID"},{"displaytag.tracking.itemName":"Item Name"},{"displaytag.tracking.itemType":"Type"}]' remove the double quotes at front and at end use single quotes

Answer 1

First you need to parse the JSON string into JavaScript object, and then access the required property:

var obj = JSON.parse(json);
console.log(obj[0]["portal.home"]);

In older browsers which do not have native JSON support, you should use something like Crockford's json2.js, which will give you one; please don't use eval() on JSON, as it can lead to pretty bad things all around.

Answer 2

Use $.parseJSON (or JSON.parse in modern browsers) to convert your string into a Javascript object:

var json = '[{"portal.home":"Home"},{"displaytag.tracking.id":"Item ID"},{"displaytag.tracking.itemName":"Item Name"},{"displaytag.tracking.itemType":"Type"}]';
var object = $.parseJSON(json);

In your case your JSON string will create an array, so you will need to get the object at the correct index:

var portalHomeValue = object[0]["portal.home"];

• Allan Kimmer Jensen: For old browsers you can use JSON2. If you don't use jQuery.
• Bhuvan: This json object is coming after parsing var obj = jQuery.parseJSON(response)
• Salman: @bhuvan if its an object then use obj[0]['portal.home']
• Matt Zeunert: @bhuvan If I paste the following into the console I don't get an error and "Home" is returned: var json = '[{"portal.home":"Home"},{"displaytag.tracking.id":"Item ID"},{"displaytag.tracking.itemName":"Item Name"},{"displaytag.tracking.itemType":"Type"}]'; var object = $.parseJSON(json); console.log(object[0]["portal.home"])
• Bhuvan: nope.. The actual response coming from controller is "{"jsonData":"[{\"portal.home\":\"Home\"},{\"displaytag.tracking.id\":\"Item ID\"},{\"displaytag.tracking.itemName\":\"Item Name\"},{\"displaytag.tracking.itemType\":\"Type\"}]","jsonDataMake":null,"jsonDataModel":null,"jsonDataSoftwareVersion":null,"jsonItemProperties":null,"jsonPositionMethods":null}". After var object = $.parseJSON(json); the response becomes '[{"portal.home":"Home"},{"displaytag.tracking.id":"Item ID"},{"displaytag.tracking.itemName":"Item Name"},{"displaytag.tracking.itemType":"Type"}]'

Answer 3

In case you have the JSON directly in your javascript source (which I don't assume, but I'm adding this for others), you can just remove the quotes, and javascript creates an object based on it:

var obj = [{"portal.home":"Home"},{"displaytag.tracking.id":"Item ID"},{"displaytag.tracking.itemName":"Item Name"},{"displaytag.tracking.itemType":"Type"}];
console.log(obj[0]["portal.home"]);

• VisioN: well, following your logic, it is better to use console.log("Home") as a solution.

Answer 4

You can directly access by following

var data = JSON.parse('[{"Item_Number":"M71118LHB","Description":"MENS ONESIE"}]');
var desc = data[0].Description;
console.log(desc);