Javascript array deletion for garbage collection

Question

I have a javascript array of objects that are each created with 'new'. In the event of an error I would like to clear the whole array so that it would be GC'ed by the JS engine. To this end is it sufficient to just set the array variable to 'null' or do I need to splice all the elements from the array and set them to null before setting the array variable to 'null'?

The reason I am asking is that in Firefox I displayed (console.log) the array before assigning it to null and the displayed object (which is usually updated in the display I assume even later) still shows the elements of the array when I inspect it later, hence my doubt if the elements are actually being free'd or not.

Answer 1

To clear an array you can just set the length to zero:

var arr = [1,2,3,4,5];

console.log(arr);
arr.length=0;
console.log(arr);

Result:

[1, 2, 3, 4, 5]
[] 

Edit: Just found this on the topic: http://davidwalsh.name/empty-array

Looking at the comments it seems that just setting the variable to a new array is the simplest method:

arr = [];

According to the test results the memory is GC'd quicker than setting the length to 0. I would imagine this is to do with the allocations triggering the GC.

There is an interesting performance test on various methods here: http://jsperf.com/array-destroy