Is the value returned by ruby's #hash the same across interpreter instances?

Is the value returned by ruby's #hash the same across interpreter instances?

For example, if I do "some string".hash, will I always get the same number even if run in different instances of the interpreter? If so, is this also true for all the开发者_JAVA技巧 builtin types (e.g. Hash, FixNum, etc).

Not the same in different instances, at least with Ruby 1.9.1.

This link gives some further info...

It seems that they changed hash algorithm in 1.9 to a random seed-based one...

If you want to do something that you know will be the same across versions and objects try md5 or sha1.

require 'digest/md5'

Digest::MD5.hexdigest('some string')