Parsing JSON data and checking if array is empty

Question

I'm trying to get an array from a JSON object, and check if it's empty, but it's giving me problems. HTML:

<p id="r"></p>

JS:

var r = document.getElementById('r');

var obj = {
    "_id": "4345356",
    "title": "sdfsf",
    "data": []
};

obj = JSON.parse(obj);

function isEmpty(a) {
    if (typeof a === 'undefined' || a.length == 0)
        return true;

    return false;
}

r.innerHTML = isEmpty(obj.data);

Fiddle. What did I miss? Thanks!

obj already is a JavaScript object, why do you want to parse() it again ? — Sirko
– Sirko, Commented Jul 19, 2014 at 10:38

Mritunjay · Accepted Answer · 2014-07-19 10:38:53Z

3

You don't have to parse the obj. It's already an object.

remove this line

obj = JSON.parse(obj);

answered Jul 19, 2014 at 10:38

Mritunjay

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Comments

Igwe Kalu · Accepted Answer · 2014-07-19 11:00:08Z

1

As others have suggested, it appears you don't have a need what whatsoever for

obj = JSON.parse(obj);

Finally to check emptiness of an array is easy, in your case, do this:

r.innerHTML = !obj.data.length;

or

r.innerHTML = obj.data.length === 0;

But if you really have a need to define a function for this purpose, then the following should be enough:

function isEmpty(a) {
    return a && !a.length;
}

answered Jul 19, 2014 at 11:00

Igwe Kalu

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Comments

Ruchir Gupta · Accepted Answer · 2014-07-19 10:40:38Z

0

You don't need this line: obj = JSON.parse(obj); I have updated the fiddle.

answered Jul 19, 2014 at 10:40

Ruchir Gupta

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