Implementation change to .NET's Random()

Question

I am migrating a method that is used for decoding from .NET Framework 1.1 to .NET Framework 4. I noticed that implementation of Random changed. So given the same seed, Rando

Answer 1

No answer here but contrary to many people here I don't think that documenting ridiculous behaviour is enough to justify it.

Because why would you provide a seeding mechanism in the first place? Well I'll tell you: so that you can always reproduce a random sequence from a single seed rather than having to persist perhaps millions of random numbers. Note that I said 'always', and not 'until you upgrade to the next version of .NET'. By not being consistent across versions the current .NET random number generators do not provide this functionality. Microsoft should have done a better job of implementing this (or not have implemented it at all) instead of just documenting the defective behaviour.

And by the way, although the algorithm is indeed an implementation detail, how on earth can you call the result of a method call an implementation detail? Should I really have to check the documentation of every method in the .NET framework to be sure that in the next version I do not risk getting a different result from concatenating two strings or calculating a square root?

So in my opinion what we have here is simply a badly implemented random number generator. And of course the entire problem could have been easily avoided by giving the new functionality (based on the new implementation) a different name.