Map.keys() returns a MapIterator object which can be converted to Array using Array.from : let keys = Array.from( myMap.keys() ); // ["a", ... ... <看更多>

JavaScript's Array.from function lets you create an array from an iterable object, such as a string, another array, or a generator function. ... <看更多>

Because the keys of a Map object are unique, creating a Map from the array of array removes the duplicate object by key (id in this case). ... <看更多>