In this chapter, you learned about dictionaries and how to add, remove, and get elements among other methods. You also learned the difference between a dictionary and a set.
We covered hashing, how to create a hash table (or hash map) data structure, how to add, remove, and get elements, and also how to create hash functions. You learned how to handle collision in a hash table using two different techniques.
We also covered how to use the ES6 Map class and also the WeakMap and WeakSet classes.
In the next chapter, you will learn a new data structure called tree.