JS: Map.prototype.size

By Xah Lee. Date: .

New in ES2015.

map_obj.size → returns the total count of entries in map_obj.

// size of map
const m = new Map([[3, "n3"], [4, "n4"], [5, "n5"] ]);
console.log(m.size) // 3

Reference

ECMAScript 2015 §Keyed Collection#sec-get-map.prototype.size

JS Map Topic

  1. the Map Object Tutorial
  2. Map Object
  3. Map.prototype
  4. Iterate Over Map Object
  5. Convert Object to/from Map
  6. Map Filter
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