Convert ten character classification string into four character one in C#

Posted by mare on Stack Overflow See other posts from Stack Overflow or by mare
Published on 2010-05-28T09:22:31Z Indexed on 2010/05/28 9:31 UTC
Read the original article Hit count: 194

Filed under:

c#

|

hash

What's the best way to convert (to hash) a string like 3800290030, which represents an id for a classification into a four character one like 3450 (I need to support at max 9999 classes).
The hash needs to be unique and always the same for the same an input.
If possible, the hash should also be reversible (but this is not required).

© Stack Overflow or respective owner

Related posts about c#

.NET WebRequest.PreAuthenticate not quite what it sounds like

as seen on West-Wind - Search for 'West-Wind'
I’ve run into the problem a few times now: How to pre-authenticate .NET WebRequest calls doing an HTTP call to the server – essentially send authentication credentials on the very first request instead of waiting for a server challenge first? At first glance this sound like it should be easy:… >>> More
HttpWebRequest and Ignoring SSL Certificate Errors

as seen on West-Wind - Search for 'West-Wind'
Man I can't believe this. I'm still mucking around with OFX servers and it drives me absolutely crazy how some these servers are just so unbelievably misconfigured. I've recently hit three different 3 major brokerages which fail HTTP validation with bad or corrupt certificates at least according to… >>> More
The dynamic Type in C# Simplifies COM Member Access from Visual FoxPro

as seen on West-Wind - Search for 'West-Wind'
I’ve written quite a bit about Visual FoxPro interoperating with .NET in the past both for ASP.NET interacting with Visual FoxPro COM objects as well as Visual FoxPro calling into .NET code via COM Interop. COM Interop with Visual FoxPro has a number of problems but one of them at least got a lot… >>> More
Dynamic Type to do away with Reflection

as seen on West-Wind - Search for 'West-Wind'
The dynamic type in C# 4.0 is a welcome addition to the language. One thing I’ve been doing a lot with it is to remove explicit Reflection code that’s often necessary when you ‘dynamically’ need to walk and object hierarchy. In the past I’ve had a number of ReflectionUtils that used string based expressions… >>> More
Finding a Relative Path in .NET

as seen on West-Wind - Search for 'West-Wind'
Here’s a nice and simple path utility that I’ve needed in a number of applications: I need to find a relative path based on a base path. So if I’m working in a folder called c:\temp\templates\ and I want to find a relative path for c:\temp\templates\subdir\test.txt I want to receive back subdir\test… >>> More

Related posts about hash

Problem with hash function: hash(1) == hash(1.0)

as seen on Stack Overflow - Search for 'Stack Overflow'
I have an instance of dict with ints, floats, strings as keys, but the problem is when there are a as int and b as float, and float(a) == b, then their hash values are the same, and thats what I do NOT want to get because I need unique hash vales for this cases in order to get corresponding values… >>> More
Hash table vs Hash list vs Hash tree?

as seen on Stack Overflow - Search for 'Stack Overflow'
What property makes Hash table, Hash list and Hash tree different from each other? Which one is used when? When is table superior than tree. >>> More
Constructing a hash table/hash function.

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I would like to construct a hash table that looks up keys in sequences (strings) of bytes ranging from 1 to 15 bytes. I would like to store an integer value, so I imagine an array for hashing would suffice. I'm having difficulty conceptualizing how to construct a hash function such that given… >>> More
Hash of unique value = unique hash?

as seen on Stack Overflow - Search for 'Stack Overflow'
Theoretically does hashing a unique value yield a unique value? Let's say I have a DB table with 2 columns: id and code. id is an auto-incrementing int and code is a varchar. If I do ... $code = sha1($id); ... and then store $code into the same row as $id. Will my code column be unique as well… >>> More
EMERGENCY - Major Problems After Perl Module Installed via WHM

as seen on Stack Overflow - Search for 'Stack Overflow'
I attempted to install the perl module Net::Twitter::Role::API::Lists using WHM and after doing so my whole site came down. It seems that something that was updated with the install isn't functioning correctly and since our website it written in Perl none of our site scripts will run. In almost 8… >>> More