Array is not a data type in Javascript?

Question

According to Professional Javascript for Web developers array is not a datatype in Javascript:

❑   “undefined” if the value is undefined 
❑   “boolean” if the value is a Boolean 
❑   “string” if the value is a string 
❑   “number” if the value is a number
❑   “object” if the value is an object or null 
❑   “function” if the value is a function

Is that correct?

Answer 1

This is correct, Array is just a descendant of object . Note though it does override a few things, for example .toString() in an array prints it's members in a comma list, instead of "[Object object]" like a plain object would.

Answer 2

I believe that is because an "Array" is an "object"

http://jsfiddle.net/z5Gv2/

Answer 3

As others say it's treated as "object". You can test for an object being an array by checking if its constructor is === to Array.

Answer 4

Arrays are not a data type in Javascript because under the hood they are objects with key:value pairs. Where the keys are the index and values are the array content. For example

let example = ["a","b","c","d","e"]

is the same as an object representation

let example = {
0: "a",
1: "b",
2: "c",
3: "d",
4: "e"
};

Answer 5

yes , Array is not a data type in JavaScript. The set of types in JavaScript are of Primitive values and Objects.

So Array falls under the category of Objects.