A hash table is a data structure that maps keys to values for highly efficient lookup.
A simple way to implement may be like this:
- Compute the key’s hash code. Two different keys could have the same hash code.
- Map the hsh ode to an index in the array. Can be done like hash(key) % array_length.
Worst case runtime is O(n). Assume good implementation that keeps collisions to minimum, lookup time is O(1).
Implementing a Hash Table Using Swift
Following Ray Wenderlich