30-seconds-of-code/snippets/uniqueSymmetricDifference.md

uniqueSymmetricDifference

Returns the unique symmetric difference between two arrays.

Use Array.filter() and Array.includes() on each array to remove values contained in the other, then create a Set from the results, removing duplicate values.

const uniqueSymmetricDifference = (a, b) => [
  ...new Set([...a.filter(v => !b.includes(v)), ...b.filter(v => !a.includes(v))])
];

uniqueSymmetricDifference([1, 2, 3], [1, 2, 4]); // [3, 4]
uniqueSymmetricDifference([1, 2, 2], [1, 3, 1]); // [2, 3]