JS Practice — Built-in Objects

Map size — two entries

📖 Usage Example

const m = new Map([['a', 1], ['b', 2]])
console.log(m.size)   // → 2
m.set('c', 3)
console.log(m.size)   // → 3

Read Map.size to get the number of key-value pairs in the map.

Map.prototype.size

After adding two different keys, size equals 2.

Challenge: Verify that new Map([['a',1],['b',2]]).size equals 2.

💡 Hints (1)