Hands-On Data Structures and Algorithms with JavaScript

Memory management

The official definition of a WeakMap as per MDN (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakMap) is as follows:

The WeakMap object is a collection of key/value pairs in which the keys are weakly referenced. The keys must be objects and the values can be arbitrary values.

The key emphasis is on weakly referenced. 

Before comparing Map and WeakMap, it is crucial to understand when to use a particular data structure. If you need to know the keys of the collection at any time or if you need to iterate over your collection, then you will need to use a Map over a WeakMap because keys are not enumerable, that is, you cannot get a list of the keys available in the latter, as it only maintains ...