Learning JavaScript Data Structures and Algorithms

Chapter 7. Dictionaries and Hashes

In the previous chapter, we learned about sets. In this chapter, we will continue our discussion about data structures that store unique values (non-repeated values) using dictionaries and hashes.

Sets, dictionaries, and hashes store unique values. In a set, we are interested in the value itself as the primary element. In a dictionary (or map), we store values as pairs as [key, value]. The same goes for hashes (they store values as pairs as [key, value]); however, the way that we implement these data structures is a little bit different, as we will see in this chapter.

Dictionaries

As you have learned, a set is a collection of distinct elements (non-repeated elements). A dictionary is used to store [key, value] ...