Remove Duplicates with Set
Deduplicate an array using Set.
Code
JavaScript
const arr = [1, 2, 2, 3, 1, 4, 3];
// Simple (order may change for primitives)
const unique = [...new Set(arr)];
console.log(unique); // [1, 2, 3, 4]
// Preserve order for objects (by key)
const seen = new Set();
const filtered = arr.filter((x) => {
const key = JSON.stringify(x);
if (seen.has(key)) return false;
seen.add(key);
return true;
});Line-by-line explanation
- 1.Set stores unique values only.
- 2.Spread [...new Set(arr)] converts back to array.
- 3.For objects, use a Set of stringified keys to preserve order.
Expected output
[1, 2, 3, 4]