Get length of array in object with unknown key

Question

I would like to get length of the array in this object:

obj = {'2012-08-08':[1,2,5,8]}

I understand we can get length like this:

obj['2012-08-08'].length

But if it is not known the name of the key how we get the length of the array?

Say I have a loop:

_.each(dates, function(date){
     //each date is like the above javascript object, how to  get the length of the array?

})

This is beginning to feel like a lost battle, but still: that is not a JSON object. — JJJ
– JJJ, Commented Jun 10, 2013 at 20:05
Using variable names is a BAD idea. Leave variables for data and make structure easily predictable. Something like {date:'2012-08-08', values:[1,2,5,8]} will do the trick better. — David Jashi
– David Jashi, Commented Jun 10, 2013 at 20:06
That looks like underscore.js to me, not jQuery. If you've actually aliased jQuery to _, then please switch the tag back. — Paul
– Paul, Commented Jun 10, 2013 at 20:17

Jacob · Accepted Answer · 2013-06-10 20:05:00Z

2

You have a date parameter in your call to each. Just call date.length.

answered Jun 10, 2013 at 20:05

Jacob

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1 Comment

You can do a for loop or use each again.