How to assign values to JSON object

Question

I have the following code that does not work. I am trying to push the text "John" onto the end of the object. I am more familiar with PHP, and this works in PHP.

var data = {};
var field_name = "first_name";

data[field_name]['answers'][] = "John";

alert(data['first_name']['answers'][0]);

Edit:

I also tried the following and it did not work.

var data = {};
var field_name = "first_name";
var i=0;

data[field_name]['answers'][i] = "John";

alert(data['first_name']['answers'][0]);

Daniel Elliott · Accepted Answer · 2012-04-12 16:33:30Z

1

try this:

var data = {};
var field_name = "first_name";
data[field_name] = {};
data[field_name].answers = [];
data[field_name].answers.push("John");

alert(data['first_name'].answers[0]);

edited Apr 12, 2012 at 16:33

answered Apr 12, 2012 at 16:22

Daniel Elliott

22.9k10 gold badges67 silver badges82 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Stephen305 Over a year ago

That's not working for some reason. I tested your code exactly as it is written.

Daniel Elliott Over a year ago

Added another line please retry

mplungjan Over a year ago

answers need to be in an object first: jsfiddle.net/mplungjan/EVsM2 var dataObj = { "first_name":{ "answers":["John"] } }

Stephen305 Over a year ago

It works. Thanks. What if I wanted to assign the value using JSON instead of a Javascript array (like in the second example I gave above)? Is that possible?

Stephen305 Over a year ago

Thanks mplungjan. I think I understand.

|

BraedenP · Accepted Answer · 2012-04-12 16:40:34Z

0

One can't arbitrarily define more array dimensions or dynamically extend bounds like PHP will happily allow. You'll need to do something like this (the shorthand [ ] notation can also be used in place of new Array(). I just prefer this way.):

var data = {};
var field_name = "first_name";

//Create the new dimensions
data[field_name] = new Array();
data[field_name]['answers'] = new Array();
//Push the new element
data[field_name]['answers'].push("John");

alert(data['first_name']['answers'][0]);

edited Apr 12, 2012 at 16:40

answered Apr 12, 2012 at 16:35

BraedenP

7,2354 gold badges35 silver badges44 bronze badges

1 Comment

mplungjan Over a year ago

var data = new Array() should be var data = {} and data[field_name] = new Array(); should be data[field_name] = {} and data[field_name]['answers'] = new Array(); should be data[field_name]['answers'] = [];

Collectives™ on Stack Overflow

How to assign values to JSON object

2 Answers 2

6 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related