Are there ideal array sizes in JavaScript?

You'll have to measure performance because there are too many moving parts. The VM and the engine and browser. Then, the virtual memory (the platform windows/linux, the physical available memory and mass storage devices HD/SSD). And, obviously, the current load (presence of other web pages or if server-side, other applications).

I see little use in such an effort. Any ideal size for performance may just not be ideal anymore when another tab loads in the browser or the page is loaded on another machine.

Best thing I see here to improve is development time, write less and be quicker on deploying your website.

Arrays in javascript are at their core objects. They merely act like arrays through an api. Initializing an array with an argument merely sets the length property with that value.

If the only argument passed to the Array constructor is an integer between 0 and 232-1 (inclusive), this returns a new JavaScript array with length set to that number. -Array ^MDN

Also, there is no array "Type". An array is an Object type. It is thus an Array Object ^{ecma 5.1}.

As a result, there will be no difference in memory usage between using

var one = new Array();
var two = new Array(1000);

aside from the length property. When tested in a loop using chrome's memory timeline, this checks out as well. Creating 1000 of each of those both result in roughly 2.2MB of allocation on my machine.

one

two