JS Practice — Built-in Objects

Map keys() — spread to array

📖 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() returns an iterator of the Map's keys in insertion order.

Challenge: Verify that spreading keys() gives the correct array.

💡 Hints (1)