Most intelligent way of filtering between two arrays filled with objects

[john098]

I have 2 different arrays filled with objects which have properties

Let’s name them arrays A and B

I want array A to have all the items B has and removing all items A has that B does not have.

Essentially is B has an item A already has, it does nothing. If B has an item A does not have, it adds it. And if A has an item B does not have, it removes it.

And finallly after all that I get the final result of array A

What’s the best way to do this?

[hbar1st]

Are you asking how to compare two objects or are you just confused about the algorithm that would help you identify which objects should be transferred from a to b?

[bvanb]

If A has all the items in B, and none of the items that are not in B, then you can simply make A a copy of B, unless you want to preserve the original order of the items in A.

[DanCouper]

@john098

Let’s name them arrays A and B

I want array A to have all the items B has and removing all items A has that B does not have.

Essentially is B has an item A already has, it does nothing. If B has an item A does not have, it adds it. And if A has an item B does not have, it removes it.

And finallly after all that I get the final result of array A

What’s the best way to do this?

From your description (albeit I don’t think it’s actually what you meant):

function example(a, b) {
  return b;
}

Your spec says want A to be B

[kevinSmith]

@john098

Essentially is B has an item A already has, it does nothing. If B has an item A does not have, it adds it. And if A has an item B does not have, it removes it.

That’s basically an intersection, right? An array of all the things that both arrays have in common?

[kevinSmith]

Or maybe I was too rash. [Edit: yeah, now I’m seeing what Dan is saying.] If you have this:

const arrA = [1, 2, 3]
const arrB = [2, 3, 4]

const arrC = myFunc(arrA, arrB)

What do you expect to be in arrC?