Map() constructor

Parameters: iterable If an iterable object (such as an array) is passed, all of its elements will be added to the new Map. Each element must be an object with two properties: 0 and 1, which correspond to the key and value (for example, [[1, “one”],[2, “two”]]). If you don’t specify this parameter, or its value is null or undefined, the new Map is empty.

Syntax example: new Map()