What is the role of a hash function in implementing a hash map (HashMap)?

The hash function in the HashMap implementation plays a crucial role: it transforms an object's key into a numerical value (hash code), which is then used to determine the index in the array of buckets.

Main tasks of the hash function:

• Distribute keys evenly across buckets to minimize collisions.
• Compute quickly to ensure high performance of operations.

Example: if you have a key, such as a string, the hashCode() method returns a number, which then, through additional processing (for example, taking the remainder by the array size), determines the position in the HashMap.