Find out length of an array which is in Object notation

Question

Here is my array

var linkArray = {
boothsizeDiv_link: false,
furnishingsprovidedDiv_link: false,
electricalDiv_link: false,
rentalfurnishingsDiv_link: false,
gesgraphicsDiv_link: false,
geslaborDiv_link: false,
contractorDiv_link: false,
carpetingDiv_link: false,
boothlightingDiv_link: false,
javitsDiv_link: false,
boothsealDiv_link: false,
mannequinsDiv_link: false,
calcDiv_link: false
};

How to find out this array length? I have googled it but no use..

It's look like a JSON string, you need to parse it first. But before that correct the notation. — Sudip Pal, Mar 14 '13 at 10:47
duplicate of http://stackoverflow.com/questions/126100/how-to-efficiently-count-the-number-of-keys-properties-of-an-object-in-javascrip — Creynders, Mar 14 '13 at 10:50

score 4 · Accepted Answer · answered Mar 14 '13 at 10:49

4

Like this:

Object.keys(linkArray).length

answered Mar 14 '13 at 10:49

elclanrs

92,861
21
134
171

Will not work in IE8 since it has no support for `Object.keys` – Vadim Mar 14 '13 at 10:52
Yeah, but that's a topic for a different question IMO. – elclanrs Mar 14 '13 at 10:53

score 1 · Answer 2 · answered Mar 14 '13 at 10:50

1

Try this:

var i, length = 0;
for(i in linkArray) {
  if(linkArray.hasOwnProperty(i)) {
    length++;
  }
}

// Here you can use length

answered Mar 14 '13 at 10:50

Vadim

8,701
4
43
50

@Amrenda I checked, it gives 13 as expected [http://jsbin.com/ubelen/1/edit](http://jsbin.com/ubelen/1/edit) – Vadim Mar 14 '13 at 11:05

ramsesoriginal · Answer 3 · 2013-03-14T11:07:02.653

The solution would be

Object.getOwnPropertyNames(linkArray).length

but be careful, because this is NOT an array, this is a object.

And beware that it will not work on Internet Explorers below 9.

In this MDN Article you can see how getOwnPropertyNames can be used.

If you want to use it also in Browser that don't support it, you just insert the following snippet in your script, at the beginning:

Object.getOwnPropertyNames = Object.getOwnPropertyNames || function(obj) {
    var ownProperties = [];
    var current = '';
    for(current in obj) {
      if(linkArray.hasOwnProperty(current)) {
        ownProperties.push(current);
      }
    }
    return ownProperties;
}

(I just wrote it, and can't test it at the moment, but it should work)

with this snippet you simulate Object.getOwnPropertyNames in browsers that don't have it natively.

And clearly instead of getOwnPropertyNames you can also use keys

Array is also and Object in JavaScript. The above will not work because length property is defined for an Array and some other objects in JS but not for "Object". — Alok Swain, Mar 14 '13 at 10:54
Yes, sorry, i pressed "post" prematurely. Editetd to correct it. And yes, every array is an object, but not every object is an array (although you can access the members through the `[]` notation) — ramsesoriginal, Mar 14 '13 at 10:58

Find out length of an array which is in Object notation

3 Answers3