JS Practice — Built-in Objects

Map keys() — empty Map

📖 Usage Example

const m = new Map([['a', 1], ['b', 2]])
for (const k of m.keys()) {
  console.log(k) // 'a', 'b'
}

Use Map.keys() to iterate over all keys in insertion order.

Map.prototype.keys()

keys() on an empty Map produces an empty iterator.

Challenge: Verify that spreading keys() of an empty Map gives an empty array.

💡 Hints (1)