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..

• Sudip: It's look like a JSON string, you need to parse it first. But before that correct the notation.
• Creynders: that's not an array, that's an object
• Creynders: duplicate of stackoverflow.com/questions/126100/…

Answer 1

Like this:

Object.keys(linkArray).length

• Vadim: Will not work in IE8 since it has no support for Object.keys
• elclanrs: Yeah, but that's a topic for a different question IMO.

Answer 2

Try this:

var i, length = 0;
for(i in linkArray) {
 if(linkArray.hasOwnProperty(i)) {
 length++;
 }
}
// Here you can use length

• Vadim: @Amrenda I checked, it gives 13 as expected http://jsbin.com/ubelen/1/edit

Answer 3

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

• Alok Swain: 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".
• ramsesoriginal: 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)