我应该清除未使用的javascript数组吗？

Question

I'm working on a page that, eventually, could have more than 100 arrays, only a few of which would be used at any given time.

At the moment, I'm populating all arrays as global variables, but I suspect this is inefficient in terms of memory use.

Should I change my code to clear the arrays when they are not being used? If so, what is the best way to do this? I'd guess var myArray = new array() but perhaps there's a better option.

Answer 1

Unless you have many thousands of objects in your arrays, you don't need to worry. Don't prematurely optimize your code; the browser is quite good at handling lots of small objects.

If memory does become an issue or you notice performance issues, you can simply reassign a new array to those variables:

myArray = [];

The garbage collector will clean up the objects that you dereferenced.

In a broader case, if there's no need to keep references to those objects, you don't even need the arrays to begin with. Ie, if you never access the elements that you put in the arrays a second time, just remove the arrays and don't bother assigning the data.