How HashMap Works Internally

Suppose a list holds one million student records. Finding one student by name can take up to one million comparisons, because the program may need to inspect every record. A HashMap with the same one million entries usually finds the student after checking one or two entries.

This speed comes from one idea: the key itself tells the map where to look. This lesson places four students in a HashMap to show how that works, what happens when two keys need the same location, and why the map sometimes moves its entries to a larger table.

The Table of Buckets

**A `HashMap