In the previous section, we have seen how to implement HashMap. Though it is one of the best data structures for key-value pairs, we still can learn other similar data structures that have slightly different approaches to achieving the same goal. ArrayMap is one of them. Before we go ahead with the implementation of ArrayMap, let's first understand the difference between this and HashMap to understand why we even need ArrayMap and where can we use it:
- HashMap uses Nodes to store key-value pairs. So, in addition to the actual data, it also allocates memory for the reference to the next node, whereas ArrayMap doesn't need this.
- To avoid hash collisions, HashMap creates a larger array even though most of the indexes could be empty, whereas ArrayMap doesn't require this.
We'll understand more about the aforementioned points in later parts...