JS Built-ins
← Map6 / 55
Mapsizebeginner

Map size — empty Map

📖 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 returns the number of key-value pairs. An empty Map has size 0.

Challenge: Verify that new Map().size equals 0.

💡 Hints (1)
  • • An empty Map has size 0