C# Hashcode Return value

It's implementation specific, and you should not rely on anything you happen to observe in one particular implementation. Only rely on what is guaranteed: two equal strings will return the same value, in the same process. The same string value can return a different hash next time you run your program, or on a different machine. This means you should never persist the result of GetHashCode - it's not useful for future comparisons.

If two strings return the same hash code they may be equal - but they may not be.