A Hash Table is a data structure in which the keys are mapped to values by means of a hashing function.
A Hash Table is a data structure in which the keys are mapped to values by means of a hashing function. The hashing function takes on input, usually of any arbitrary length, and outputs an index where the key-value pair can be found. It’s often used as an alternative to an array or dictionary because it’s faster for retrieving and inserting data than other data structures.
Hash tables are also called associative arrays, hash maps, dictionaries, symbol tables, or direct acyclic word graphs (DAWGs).
Hash Tables in python
Hash tables are one of the most used data structures in Python. They are a key-value pair and can be used as a Dictionary, which is an unordered collection of items that stores keys and their corresponding values.
The keys are unique, but the values can be duplicated. The main difference between a Hash Table and a Dictionary is that the order of items in a Dictionary is not relevant while in Hash Tables it is.
Why Would You Use a Hash Table?
A hash table is a data structure that stores information in a manner that is easy to search and update.
The benefits of using a hash table are:
- It is quick to access any given item.
- It has a good spatial locality for large tables. This means that if you look at the items near each other, they are likely to be close together in the hash table as well.
- It has a good cache locality for small tables. This means that if you look at the items near each of your CPU caches, they are likely to be close together in the hash table as well.
Pros and Cons of Hash Table
Hash tables are a data structure that stores information in an unordered way. The table is composed of keys and values where the key is used to find the corresponding value. Hash tables are used for storing large amounts of data and for fast lookups, but it is not so good for searching.
Advantages:
-Hash Tables can be used to store large amounts of data in a very efficient manner.
-It has a fast lookup time because it stores all the information in an unordered way.
-The size of the table can be adjusted easily by increasing or decreasing the number of buckets (i.e., number of partitions).
Disadvantages:
-It does not allow searching efficiently because it stores all the information in an unordered way.
Conclusion
Hash tables are most commonly used for looking up a value in a set of keys. Hash tables are an important data structure that can be used to improve the performance of many algorithms.
The conclusion for hash tables is that they are one of the most commonly used data structures and is important for many algorithms.
