There doesn’t seem to be a way to extend an existing JavaScript array with another array, i.e. to emulate Python’s extend method.
I want to achieve the following:
>>> a = [1, 2]
[1, 2]
>>> b = [3, 4, 5]
[3, 4, 5]
>>> SOMETHING HERE
>>> a
[1, 2, 3, 4, 5]
I know there’s a a.concat(b) method, but it creates a new array instead of simply extending the first one. I’d like an algorithm that works efficiently when a is significantly larger than b (i.e. one that does not copy a).
Note: This is not a duplicate of How to append something to an array? — the goal here is to add the whole contents of one array to the other, and to do it “in place”, i.e. without copying all elements of the extended array.