Will string.GetHashCode() return negative value?

c# string hash gethashcode
Eric Yin picture Eric Yin · Jan 31, 2012 · Viewed 9.7k times · Source

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

Answer

SLaks picture SLaks · Jan 31, 2012

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.

Related questions

How is GetHashCode() of C# string implemented?

I'm just curious because I guess it will have impact on performance. Does it consider the full string? If yes, it will be slow on long string. If it only consider part of the string, it will have bad performance (…

Read More
Hashing a string with Sha256

I try to hash a string using SHA256, I'm using the following code: using System; using System.Security.Cryptography; using System.Text; public class Hash { public static string getHashSha256(string text) { byte[] bytes = Encoding.Unicode.GetBytes(text); SHA256Managed hashstring = …

Read More
Hash string in c#

I have a problem when trying get a hash string in c#. I already tried a few websites, but most of them are using files to get the hash. Others that are for strings are a bit too complex. I …

Read More