How do I empty an array in JavaScript using the most effective method?

General Discussions
,
1

For example, given A = [1, 2, 3, 4];, what’s the best way to completely clear it? I was wondering if there’s something like .remove() for an empty array JavaScript operation.

2

Hi,

You can set length to 0. Here is how you can do it:

let A = [1, 2, 3, 4];
A.length = 0;
console.log(A); // []

It’s the quickest and most memory-efficient method. I often use this when resetting large data arrays in dashboards or forms.

3

You can also reassign to a new array. I use this for local variables or temporary arrays, but if other variables reference the original array, they won’t be cleared.

let A = [1, 2, 3, 4];
A = [];
console.log(A); // []
4

You can also use splice() for in-place clearing:

let A = [1, 2, 3, 4];
A.splice(0, A.length);
console.log(A); // []

This saved me in a shared-state app where multiple components referenced the same array. Splice cleared it without breaking bindings.