- Random access.
- Fixed size.
- Not Random access.
- Not fixed size.
What we need is something that has random access and not fixed size.
Solution: Hash table
Uses a hash function to determine where to store a given key value.
Same hash function is used later to search for where a given key value is stored.
If the hash output of two keys point to the same location.
Solution: each location has a linked list of values.