Way to empty an array?

Question

I read the topic How do I empty an array in JavaScript?

Answer :

Very simple:

A = [];

I am interested in the comment by Daniel Baulig:

this will NOT empty the array, but create a new, empty array. This might cause problems, especially if there are other references to the array. OP: Please consider to accept Matthew's answer instead. It is the cleaner and formally correct approach. – Daniel Baulig Jan 19 '11 at 13:08

Can you tell me what problems this could cause?

Here are some methods to clear an array http://jsperf.com/array-destroy/40 — megawac, Nov 08 '13 at 18:33
Rather than put a minus question you would have tried to understand the question... — Michael Phelps, Nov 08 '13 at 18:39

score 10 · Accepted Answer · answered Nov 08 '13 at 18:32

The problem is that you may have another reference to that array.

Consider this :

var A = ['A'];
var B = A;

If you do

A = [];

this will still let B be ['A']. That's the difference between emptying (or changing) an array, or replacing it (what you did).

When you do

A.length=0;

then B will be empty too.

Way to empty an array?

1 Answers1