Will string.GetHashCode() return negative value?

Question

I tried with batch of random strings, all values I got are positive, but I wondering:

Will String.GetHashCode() return negative or 0?

Since the return value is int, so I guess it might be, so if it is the case, I have to change my logic.

If you have answer or have some official sources, please share

vkreynin.wordpress.com/2008/07/05/explaining-gethashcode-method check this :) — Ravi Gadag
– Ravi Gadag, Commented Jan 31, 2012 at 18:22

SLaks · Accepted Answer · 2012-01-31 18:16:50Z

32

Yes, it can return negative values.

You must not have any logic that works with GetHashCode() values.
GetHashCode() is not guaranteed to be unique and can change between builds.

GetHashCode() must be treated as an opaque token that can be combined with other hashes or modded out into hashtables.

answered Jan 31, 2012 at 18:16

SLaks

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9 Comments

SLaks is right - particularly between 32-bit and 64-bit architectures.

wow, it changes between builds, that sucks, I have to use something else, thanks anyway :)

Yes; you must use something else. GetHashCode() is only for in-memory hashtables. You should probably use SHA512.

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President James K. Polk · Accepted Answer · 2025-06-03 01:00:11Z

8

edited Jun 3 at 1:00

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answered Jan 31, 2012 at 18:17

cichy

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