JSON / JavaScript get object keys

Question

I'm extracting data from as follows -

The above function returns data in the below format -

[Object { date=Date,  value=112,  volume=1469}, Object { date=Date,  value=124,  volume=539}, Object { date=Date,  value=114,  volume=859}, Object { date=Date,  value=123,  volume=1284}, Object { date=Date,  value=113,  volume=1382}, Object { date=Date,  value=129,  volume=1353}]

I would like to obtain the list of keys only as a simple array.(Parsing the first object in the array is enough to get this as all other objects have the same keys) In case of the above output, I would like the simple array to look as ["date","value","volume"]

I tried JSON.stringify & then parse but it still doesn't work.

Also, how could I convert the whole array obtained from the chart into a simple array please?

I'm visualizing an output of the below type -

[{'date':'whatever',  'value':126,  'volume':911},
{'date':'whatever',  'value':136,  'volume':1005},
{'date':'whatever',  'value':125,  'volume':720}]

If the question doesn't make sense, please let me know. I'll see how best I could re-word.

What you have there isn't valid JavaScript or JSON. Showing how you extracted that data from the chart might help someone answer. — Paul
– Paul, Commented Feb 19, 2016 at 6:22
if it is an array then just use data[0].keys() then you'll get array of keys. — rrk
– rrk, Commented Feb 19, 2016 at 6:22
I've just updated the question with the function that retrieves data from the chart. — usert4jju7
– usert4jju7, Commented Feb 19, 2016 at 6:23

rrk · Accepted Answer · 2016-02-19 06:36:05Z

6

Use Object.keys() function. Here in the response from function you get an array. Use that to get the list of keys.

var data = getChartData('param')
Object.keys(data[0]);

edited Feb 19, 2016 at 6:36

answered Feb 19, 2016 at 6:25

rrk

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11 Comments

usert4jju7 Over a year ago

Thank you Rejith. I did this - var chartData = getChartData("chartdiv"); var keysOnly = chartData[0].keys(); console.log(keysOnly); I get the error - TypeError: chartData[0].keys is not a function. Sounds like I'm missing including a library?

Paul Over a year ago

It's Object.keys not Object.prototype.keys. That would need to be called like Object.keys( data[0] ); . data[0].keys() will just throw an error because data[0].keys is `undefined|.

usert4jju7 Over a year ago

Cool. Thank you Paul & Rejith. Awesome stuff. Thank you tons.

rrk Over a year ago

@Paulpro I cant believe that I made such a silly mistake. Updated.

usert4jju7 Over a year ago

Cool. This helps. Thank you Rejith.

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