Thread by @ClassLambda

ARRAYS VS. HASH MAPS

(1/12) As promised, we will continue with twitter threads about different concepts. Today we are going to explain the differences between ARRAYS and HASH MAPS, in both structures and uses. 👇🧵

(2/12) What is the difference between arrays and hash maps? Arrays are faster for accessing an element at a specific position, and if you need to perform the same operation on all elements in the array, while hash maps are faster for looking up a value given a key.

(3/12) Arrays and hash maps are both data structures that are used to store and retrieve data. However, they differ in several ways:
▪️ Indexing
▪️ Search time
▪️ Insertion and deletion

(4/12) They are also dissimilar in:
▪️ Size
▪️ Order

(5/12) Overall, arrays are more suitable for situations where you need to access elements using a contiguous sequence of integers and you don’t need to frequently insert or delete elements.

(6/12) Hash maps are more suitable for situations where you need to access elements using keys and you need to perform frequent insertions and deletions.

(7/9) So… When should I use an array and when should I use a hash map?
It depends on what you need to do. Use an array for quick access to specific elements or ordered sequences. Use a hash map for quick look-up of values by key.

(8/12) Also, use an array if you don’t need to frequently insert or delete elements. Hash maps are more suitable for situations where you need to perform frequent insertions and deletions.

(9/12) You’d want to use hash maps in situations where you want to associate two pieces of data with one another.

(10/12) Cache locality better for arrays: using arrays can improve cache locality and lead to better performance because they allow the cache to store more data in a single cache line, increasing the chances that the data the program needs will be in the cache when it is needed.

(11/12) Remember! Hash maps do not allow for duplicate keys.

(12/12) That’s it! Both data structures have their time and place. We hope you’ve learned something about arrays and hash maps. Do you have any more questions? Let us know! #programming #datastructures #hashmaps #arrays #lambdathread