JS Practice — Built-in Objects

Map has() — existing key

📖 Usage Example

const m = new Map([['a', 1]])
m.has('a')   // → true
m.has('z')   // → false

Use Map.has() to check whether a key exists in the map.

Map.prototype.has()

has(key) returns true if the key exists in the Map.

Challenge: Verify that has() returns true for an existing key.

💡 Hints (1)