How to extend an existing JavaScript array with another array, without creating a new array?

General Discussions
2

Hey! One of the most straightforward ways is using push() along with the spread operator. So if you have:

let a = [1, 2];
let b = [3, 4, 5];
a.push(...b);

That’ll update a in place. Just a heads-up though m if b is really large, spreading it might hit the call stack limit. So it works great for small to moderate arrays, but not ideal if b has, say, 100,000+ items.