Key components of double hashing

Now that we know what double hashing is, let's look at the structure of a hash table implemented using double hashing. The hash table is just an encapsulation around an array that stores key-value pairs. Different pieces have to be put together to create a hash table. Let's look at all the components and functions needed to implement a double hashing hash table.

Record

Like quadratic probing, in a double hashing implementation of a hash table, each index in the internal array stores only one record, and collisions are handled by finding the next available free slot. For this reason, we store the key-value mapping and additional metadata to identify the type of slot (empty, deleted, or occupied) at each index in the array.