Using a larger prime as a multiplier when overriding hashCode()

Question

I have been reading about hashcode functions for the past couple of hours and have accumulated a couple of questions regarding use of prime numbers as multipliers in custom

Answer 1

• Overflow is not a problem. Hashes are constrained to a narrow value set anyway.

• The first hash function you posted isn't very good. Doing return (prime * hash1) ^ hash2; ` instead would reduce the number of collisions in most cases.

• Multiplying by a single word int is generally very fast, and the difference between multiplying by different numbers is negligible. Plus the execution time is dwarfed by everything else in the function anyay

• Using different prime multipliers for each part may reduce the risk of collisions.