jQuery, 'undefined' length of array of arrays?

Question

I have this array structure:

mdarray = {
  '0001':{address:'add1',title:'title1'},
  '0002':{address:'add2',title:'title2'},
  '0003':{address:'add3',title:'title3'}
};

I wish to only work with the array if it has one or more items in it. Usually with an array I would use if (mdarray.length > 0) {} but when I do this with the array above, mdarray.length returns 'undefined'.

Is this is because it is an array of arrays? Is there another way to very simply pull back the number if items in the root of the array?

Or it is because the keys are strings and not integers?

I've played about with different array structures and read about multidimensional arrays but I've not yet found an answer.

no this is because this is not an array at all. This is called an object literal — devnull69, Oct 16 '12 at 14:44
That isn't an array structure, that is an Object structure, and objects don't have length. — LoveAndCoding, Oct 16 '12 at 14:45

score 2 · Answer 1 · answered Oct 16 '12 at 14:45

2

That is an Object, not an Array. So it has no length!

answered Oct 16 '12 at 14:45

Hans Wassink

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score 2 · Accepted Answer · edited May 23 '17 at 11:43

2

Modified code: you are creating Object instead of Array you should use following code: see this thrad

mdarray = [
  {address:'add1',title:'title1'},
  {address:'add2',title:'title2'},
  {address:'add3',title:'title3'}
];

mdarray.length // 3

edited May 23 '17 at 11:43

Community

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answered Oct 16 '12 at 14:45

Anoop

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Note that it is not a multi-dimensional array. It is an array of objects. – jalynn2 Oct 16 '12 at 14:49
@Sushil Ah ok thanks. I think I understand the differences now, thanks for the thread link also. – Mere Development Oct 16 '12 at 15:00

jQuery, 'undefined' length of array of arrays?

2 Answers2