I'm envisioning a nice little skit that a Don Box or someone like that could
pull off on stage. Don't worry there are no bath-tubs or naked presenters
involved. It is along the lines of the typical malevolent computer/robot on
StarTrek that is defeated by a paradoxical question. In this case,
The URL you referenced says
[quote] WARNING: When an object is stored in a hash table, an application
should never change the object in a way that will change its hash code. If you
do so, the object will thenceforth be in the wrong bucket. [end quote]
I fear that MS did not make it clear enough
to the object.
- Jim
-Original Message-
From: Unmoderated discussion of advanced .NET topics.
[mailto:[EMAIL PROTECTED] On Behalf Of Ian Griffiths
Sent: Saturday, July 02, 2005 2:47 AM
To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM
Subject: Re: [ADVANCED-DOTNET] GetHashCode() method
> special cod
At 05:47 AM 7/2/2005, Ian Griffiths wrote
>> special code needs to exist to ensure that once GetHashCode()
>> has returned a value, that object instance must always return
>> the same value from later GetHashCode calls.
>
>Nope. I know the docs say that GetHashCode must always return the same
>val
ny object
> that's in use as a key.)
>
>
> So if you want to write mutable objects that implement GetHashCode you
> have two choices. (1) your GetHashCode could return a constant value,
> the same for all instances regardless of value, or (2) your object's
> hash code
ject's
hash code must change when the value changes in a way that affects the
outcome of Equals.
--
Ian Griffiths
http://www.interact-sw.co.uk/iangblog/
> -Original Message-
> From: Unmoderated discussion of advanced .NET topics.
[mailto:ADVANCED-
> [EMAIL PROTECTED] On Behalf Of J. Me
> You can get dupes with GetHashCode(); but two objects with
> the same "value" must have the same hash code.
> I'll admit that Equals() must be overridden when
> GetHashCode() is overridden; but, I disagree that
> GetHashCode() is used wherever Equals() is used.
Heh I agree, though I thin
> At 02:49 PM 6/27/2005, Frans Bouma wrote (in part)
> >> There's been some discussion lately regarding the
> >> Object.GetHashCode() method.
> >>
> >> I think the concensus is pretty clear: for best
> reliability, classes
> >> that implement GetHashCode() should be immutable.
> >
> >Why? y
On 2005-06-27 21:19, Peter Ritchie wrote:
Hashtable.ContainsKey is basically looping until (entry.key.GetHashCode()
== keyParameter.GetHashCode() && entry.key.Equals(keyParameter)) == true.
To be clear: The hashtable actually uses a bit different algorithm. The
hash code is used to determine t
See comments below.
On Mon, 27 Jun 2005 15:37:18 -0400, J. Merrill <[EMAIL PROTECTED]> wrote:
>I think the right way to say it is that if the GetHashCode result
>is computed from values of one or more properties (or fields) of
>the object, those values must be immutable -- either that, or special
You can get dupes with GetHashCode(); but two objects with the
same "value" must have the same hash code.
I'll admit that Equals() must be overridden when GetHashCode() is
overridden; but, I disagree that GetHashCode() is used wherever Equals()
is used.
As with any hash, objects of save "value" *
At 02:49 PM 6/27/2005, Frans Bouma wrote (in part)
>> There's been some discussion lately regarding the
>> Object.GetHashCode() method.
>>
>> I think the concensus is pretty clear: for best reliability,
>> classes that implement GetHashCode() should be immutable.
>
>Why? you can also get du
> There's been some discussion lately regarding the
> Object.GetHashCode() method.
>
> I think the concensus is pretty clear: for best reliability,
> classes that implement GetHashCode() should be immutable.
Why? you can also get dupes with GetHashCode. It's not as if it's a
magic value.
There's been some discussion lately regarding the Object.GetHashCode()
method.
I think the concensus is pretty clear: for best reliability, classes that
implement GetHashCode() should be immutable.
Other than the Hashtable and ProperytCollection classes, does anyone know
where GetHashCode() is us
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