JS Practice — Built-in Objects

Set union() — originals unchanged

📖 Usage Example

const a = new Set([1, 2])
const b = new Set([2, 3])
const all = a.union(b)
console.log([...all]) // → [1, 2, 3]

Use Set.union() to combine two sets into a new set containing all unique values.

Set.prototype.union() (ES2025)

union() returns a new Set and does not modify the originals.

Challenge: Verify that original Sets are unchanged after union().

💡 Hints (1)