--- title: Map --- ## Map A map of `[key, value]` entries, where keys and values can be any value (both objects and primitive values). ## Syntax ```javascript new Map([iterable]) ``` ## Parameters **iterable** An Array or other iterable object whose elements are key-value pairs. ## Example ```javascript // basic usage const myMap = new Map(); myMap.set('foo',1); myMap.set('bar',2); myMap.set('baz',3); myMap.get('foo'); // returns 1 myMap.get('baz'); // returns 3 myMap.get('hihi'); // return undefined myMap.size(); // 3 ```