How to compare arrays and remove duplicates in GAS?

Question

How to get this one to yield a list of the unique ID's after comparison?

It's giving me an empty list, although everything seems to be fine.

Answer 1

Try with filter and includes.

If you want to check for values that are in uniqueIDs1 but not in uniqueIDs2:

let uniqueIDs1 = [1,2,3,4,5,6];
let uniqueIDs2 = [1,3,4,6];
let unique_values = uniqueIDs1.filter(x => !uniqueIDs2.includes(x));
console.log(unique_values) // [ 2, 5 ]

If you want to check for values that are in uniqueIDs1 but not in uniqueIDs2 and in uniqueIDs2 but not in uniqueIDs1:

  let uniqueIDs1 = [1,2,3,4,5,6];
  let uniqueIDs2 = [1,3,4,6,10];
  let uv1 = uniqueIDs1.filter(x => !uniqueIDs2.includes(x));
  let uv2 = uniqueIDs2.filter(x => !uniqueIDs1.includes(x));
  let uv = uv1.concat(uv2);
  console.log(uv) // [ 2, 5, 10 ]