Can't select first value in json object

Question

I can't seem to select the first value inside the json object.
I've tried array[0][0], but it returns undefined.

[ { 'Room 1': 11017,
'Room 2': 2651,
'Room 3': 1,
'Room 4': 2,
'Room 5': 1,
'Room 6': 1,
'Room 7': 3,
'Room 8': 5,
'Room 9': 3661,
'Room 10': 2 } ]

Answer 1

You need to access keys using a string, not an index:

array[0]['Room 1']

Edit: There is a method to access keys based on order of definition. However, while almost all implementations of Object.keys currently return in the correct order, it is not required to do so by the spec:

var keys = Object.keys( array[0] );
var fifth = keys[4];
var value = array[0][fifth];

Answer 2

This is because it's an object inside the array. You can access an array's elements by using array[0], but for an object it'd have to be object.key or object["key"].

To make this data structure more dynamic, I'd suggest breaking it up like so:

roomNumbers = [11017, 2651, 1, 2, 1]...(and so on)

That way, you access a number without knowing the room ahead of time.

Answer 3

You have an array, containing 1 object, which has keys and not indexes. So reference the first key:

array[0]['Room 1']

If you need to pull without know the key names, you can get them via Object.keys(obj);

var availableKeys = Object.keys(array[0]);
var val = array[0][availableKeys[0]]; //replace availableKeys index with what you need

Answer 4

Since the element is an object, it's trying to retrieve property 0 which is undefined. So you need to use the property name to get the value (eg : array[0]['Room 1']).

---

You can use Object.keys() to get the key array then get the value using that. But there is no guarantee of the order, since Object.keys() returns keys in an arbitrary order.

var array = [{
  'Room 1': 11017,
  'Room 2': 2651,
  'Room 3': 1,
  'Room 4': 2,
  'Room 5': 1,
  'Room 6': 1,
  'Room 7': 3,
  'Room 8': 5,
  'Room 9': 3661,
  'Room 10': 2
}]

console.log(
  array[0][Object.keys(array[0])[0]]
);

---

UPDATE : If you want to get it in certain order then use a nested array instead.

var array = [[
  11017,
  2651,
  1,
   2,
   1,
   1,
   3,
   5,
   3661,
   2
]]

console.log(
  array[0][0]
);