Checking if Json object is empty

Question

I use Jquery to check if my object from an ajax call is empty or not.

In this example I have made a correct AJAX call and it returns some data.

console.log ("obj before Json parse: ",response);
var test = $.isEmptyObject(response);
console.log("test if object is empty:",test);

obj before Json parse:  [{"dateTime":"2015-10-02","entries":220}]
est if object is empty: false

However in this example I have made an incorrect AJAX call that returns nothing.

console.log ("obj before Json parse: ",response);
var test = $.isEmptyObject(response);
console.log("test if object is empty:",test);

obj before Json parse:  []
test if object is empty: false

surely the test variable should be true in this case as the object is empty?

Possible duplicate of How do I test for an empty Javascript object? — Diptox
– Diptox, Commented Oct 12, 2015 at 10:54
isEmptyObject should only be used on plain objects, you seem to have an array, and could just do response.length instead. — adeneo
– adeneo, Commented Oct 12, 2015 at 10:54

Tushar · Accepted Answer · 2015-10-12 11:02:15Z

7

Use length to check if the object is empty or not.

var isEmpty = (response || []).length === 0;

edited Oct 12, 2015 at 11:02

answered Oct 12, 2015 at 10:54

Tushar

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10 Comments

Andreas Uldall Leonhard Over a year ago

I should probably use response.length; then. Because I just tested isPlainObject and it returned false in both cases.

Tushar Over a year ago

@AndreasUldallLeonhard isPlainObject works on Objects, if the response is array, use arr.length to check if it is empty

user5325596 Over a year ago

response.length will throw an error if response is null or undefined. You could be more defensive and have var test = response && response.length.

Tushar Over a year ago

@user5325596 Thanks for the case, I've updated answer

Andreas Uldall Leonhard Over a year ago

Hmm this makes no sense at all obj before Json parse: [{"dateTime":"2015-10-02","entries":220}] index.html:335 test if object is empty: 41 obj before Json parse: [] test size of object: 2 That's what happened when I did .length on both

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Yaseen Ahmad · Accepted Answer · 2017-04-24 12:44:54Z

-1

var jsonData = JSON.parse(responseBody);
tests['empty_or_not'] = jsonData.length === 0;

edited Apr 24, 2017 at 12:44

Yaseen Ahmad

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answered Apr 24, 2017 at 9:16

Madhusudhan R

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