Javascript new Array and join() method

Question

Inspired by this popular speech I wanted to figure out some issue related to creating arrays. Let\'s say I am creating new array with:

Array(3)

Answer 1

join joins the elements together, using what was passed as a joiner. So you have three empty strings "surrounding" the lorems:

|lorem|lorem|

It might be a little more obvious if you don't use an empty array:

var arr = [1, 2, 3, 4, 5]; // Like Array(5), except not sparse

arr.join('-and-'); // 1-and-2-and-3-and-4-and-5

And your first example join output, by the way, is incorrect. It should be ,, or ",,". (Depends on the output format.)