Why doesn’t deleting from a Javascript array change its length?

Question

I have an array:

data.Dealer.car[0]
data.Dealer.car[1]
data.Dealer.car[2]

If I do this:

alert(data.Dealer.car.length);
dele         


        

Answer 1

Building on what @Ray Hidayat posted:

JavaScript arrays are sparse. If you have an array of length 3, deleting the reference at [1] will simply "unset" that item, not remove it from the array, or update that array's length. You could accomplish the same with

myArray = [0, , 2, , , , ];  // length 6; last three items undefined

Here's a Fiddle: http://jsfiddle.net/WYKDz/

NOTE: removing items from the middle of large arrays can be computationally intensive. See this post for more info: Fastest way to delete one entry from the middle of Array()