JS Practice — Built-in Objects

Map size — is a number

📖 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

The size property is always a non-negative integer.

Challenge: Verify that typeof new Map().size is 'number'.

💡 Hints (1)