Object members with value of type "undefined" should be removed

[Krinkle]

From mcknut on September 29, 2009 14:12:02

What steps will reproduce the problem? 1. var a = {foo:undefined}
2. $.toJSON(a) 3. What is the expected output? What do you see instead? Expected: {"foo":null}
See this instead: {"foo":undefined} What version of the product are you using? On what operating system? 2.2 Please provide any additional information below. The JSON spec here shows that undefined is not valid, it should be null: http://json.org/ Fix is pretty simple so I haven't attached a patch.

Original issue: http://code.google.com/p/jquery-json/issues/detail?id=27

[Krinkle]

From shuoink on May 20, 2010 08:09:55

I'm having this issue as well and it appears to work fine on IE8 and other modern
browsers that have native JSON.

Example:
{foo: 'bar', baz: undefined }

In IE8,chrome,firefox i get the following:
{"foo": 'bar'}

In IE8-Compat (and I assume IE 7), i get this:
{"foo": 'bar', "baz": undefined }

Thus, my app breaks in IE7 unless I explicitly convert undefined to null before
serialization.

[Krinkle]

From kldavis4 on July 28, 2010 04:27:25

Same problem here ... This is an issue for me because I am using a 3rd party library so I don't have (much) control over whether properties are set to undefined or null. Appears to only be an issue in IE for me. I have switched to using json2 for now.

[Krinkle]

From frawl021 on October 04, 2010 07:48:04

Add to line 103 to fix:

            if (typeof o[k] == 'undefined')
                continue;  // undefined is not a valid JSON value.

[Krinkle]

From krinklemail on September 17, 2011 17:53:41

Added a test case for this in r24 . It is indeed failing.

Summary: Object members with value of type "undefined" should be removed

[Krinkle]

From krinklemail on September 17, 2011 17:55:10

Fixed in r26

Status: Fixed

[Krinkle]

From krinklemail on September 17, 2011 20:03:16

Issue #46 has been merged into this issue.