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HashTable

Goal​

Keeping data retrieval in constant while also maintaining dynamism.

Mechanics​

The Hashtable is comparable in nature to an array where we are basically trying to index our data in sequential fashion. Where it differs is how the data is placed, the hashing function determines the location.

Our focus needs to be on:

  • resizing our table
  • determining a hashing function

Hashing function​

Note: All types of data can be converted to an integer following a numerical ascii conversion

A hashing function takes the hash code of your data, then applies some kind of a modulus operation on the size of the hashtable.

For example, if we have a table size of 7, and we want to insert data with a hashed value of 48, it will be inserted at index 6.

Optimal Hashing​

A good hashing function:

  • Distributes values as uniformly (on the available keys in the memory space) as possible to reduce collisions
  • Is easy and fast to calculate.