Why Prime number for Hashcode??

[pawan chopra]

Hi All,

I would like to know that why do we use prime number in Hash code implementation.

[Adam Michalik]

I don't have deep knowledge on the implementation of hashing algorithms, but I know that using prime numbers minimizes collisions. See Wiki for a short explanation.

[Campbell Ritchie]

It is more likely to produce slight differences in the right-hand bits of the number. Since HashMap etc use something analogous to hash % 16, hash % 32 etc, the lower-order bits are where differences are beneficial.

[Jesper de Jong]

We recently had a topic with a similar question and I wrote a long answer to it. Read it here.

[pawan chopra]

Jesper Young wrote:We recently had a topic with a similar question and I wrote a long answer to it. Read it here.

Thanks Jesper I should have done some search on this before posting this question thanks alot great explanation.