Implementing a key/value pair collection...with a catch

I have an interesting problem and I'm not coming up with any answers in my
searches, so hopefully someone can give me a hand with this. I have a
feeling it's easy, but I usually get my nose stuck too far in the details to
see the big picture. :)

I want to create a collection of key/value pairs. I have a class for the
key/value pair...we'll just call it KeyValuePair for this example. Now,
when creating the collection, I need to be able to have duplicate
keys...this is why I can't just use a hashtable. One more requirement is
that I can iterate through the entire collection, or just a subset of the
collection based on a key. The final requirement is that all key/value
pairs stay in the order that I added them...I can't have them rearranged
when I iterate through them. So, let's say the following is the data stored
in the collection:

Key Value
------------
AAA Test 1
BBB Test 2
AAA Test 3
BBB Test 4
AAA Test 5
CCC Test 6
DDD Test 7
EEE Test 8
EEE Test 9

I'd like to be able to do this:

For Each keyValuePair in keyValuePairCollection.Items
Debug.WriteLine("The key is " & keyValuePair.Key & " and the value is "
& keyValuePair.Value & ".")
keyValuePair.Value = keyValuePair.Value & " has been modified"
Debug.WriteLine("The new value is " & keyValuePair.Value & ".")
Next

The above code would iterate through all 9 key/value pairs and modify their
values. I'd also like to be able to do this:

For Each keyValuePair in KeyValuePairCollection.FilteredItems("AAA")
Debug.WriteLine("The key is " & keyValuePair.Key & " and the value is "
& keyValuePair.Value & ".")
keyValuePair.Value = keyValuePair.Value & " has been modified"
Debug.WriteLine("The new value is " & keyValuePair.Value & ".")
Next

The above code would iterate through only the 3 key/value pairs with a key
of "AAA" and modify their values. So...is all of this possible? Can anyone
send me in the right direction? I'd really appreciate any help you can
give. Thanks!

re: Implementing a key/value pair collection...with a catch

Hi,

Here is a suggestion. You store any type of data in a hashtable.
Why not store an arraylist with all of your values for each key.

Ken
-----------------------
"Jeff L." <nospam@nospam.com> wrote in message
news:%23NATeCQ4DHA.2480@TK2MSFTNGP09.phx.gbl...[color=blue]
>I have an interesting problem and I'm not coming up with any answers in my
> searches, so hopefully someone can give me a hand with this. I have a
> feeling it's easy, but I usually get my nose stuck too far in the details
> to
> see the big picture. :)
>
> I want to create a collection of key/value pairs. I have a class for the
> key/value pair...we'll just call it KeyValuePair for this example. Now,
> when creating the collection, I need to be able to have duplicate
> keys...this is why I can't just use a hashtable. One more requirement is
> that I can iterate through the entire collection, or just a subset of the
> collection based on a key. The final requirement is that all key/value
> pairs stay in the order that I added them...I can't have them rearranged
> when I iterate through them. So, let's say the following is the data
> stored
> in the collection:
>
> Key Value
> ------------
> AAA Test 1
> BBB Test 2
> AAA Test 3
> BBB Test 4
> AAA Test 5
> CCC Test 6
> DDD Test 7
> EEE Test 8
> EEE Test 9
>
> I'd like to be able to do this:
>
> For Each keyValuePair in keyValuePairCollection.Items
> Debug.WriteLine("The key is " & keyValuePair.Key & " and the value is "
> & keyValuePair.Value & ".")
> keyValuePair.Value = keyValuePair.Value & " has been modified"
> Debug.WriteLine("The new value is " & keyValuePair.Value & ".")
> Next
>
> The above code would iterate through all 9 key/value pairs and modify
> their
> values. I'd also like to be able to do this:
>
> For Each keyValuePair in KeyValuePairCollection.FilteredItems("AAA")
> Debug.WriteLine("The key is " & keyValuePair.Key & " and the value is "
> & keyValuePair.Value & ".")
> keyValuePair.Value = keyValuePair.Value & " has been modified"
> Debug.WriteLine("The new value is " & keyValuePair.Value & ".")
> Next
>
> The above code would iterate through only the 3 key/value pairs with a key
> of "AAA" and modify their values. So...is all of this possible? Can
> anyone
> send me in the right direction? I'd really appreciate any help you can
> give. Thanks!
>
>[/color]

re: Implementing a key/value pair collection...with a catch

I think I get what you're saying...the problem is that if I do it that way,
the key/value pairs will no longer be correctly ordered. I need to keep
them in their original order (which can be any order at all...no specific
sorting or anything). If I stick them into a hashtable based on their key
value, they won't be ordered correctly any more.

Jeff

"Ken Tucker [MVP]" <vb2ae@bellsouth.net> wrote in message
news:Om$UOPQ4DHA.1052@TK2MSFTNGP12.phx.gbl...[color=blue]
> Hi,
>
> Here is a suggestion. You store any type of data in a hashtable.
> Why not store an arraylist with all of your values for each key.
>
> Ken
> -----------------------
> "Jeff L." <nospam@nospam.com> wrote in message
> news:%23NATeCQ4DHA.2480@TK2MSFTNGP09.phx.gbl...[color=green]
> >I have an interesting problem and I'm not coming up with any answers in[/color][/color]
my[color=blue][color=green]
> > searches, so hopefully someone can give me a hand with this. I have a
> > feeling it's easy, but I usually get my nose stuck too far in the[/color][/color]
details[color=blue][color=green]
> > to
> > see the big picture. :)
> >
> > I want to create a collection of key/value pairs. I have a class for[/color][/color]
the[color=blue][color=green]
> > key/value pair...we'll just call it KeyValuePair for this example. Now,
> > when creating the collection, I need to be able to have duplicate
> > keys...this is why I can't just use a hashtable. One more requirement[/color][/color]
is[color=blue][color=green]
> > that I can iterate through the entire collection, or just a subset of[/color][/color]
the[color=blue][color=green]
> > collection based on a key. The final requirement is that all key/value
> > pairs stay in the order that I added them...I can't have them rearranged
> > when I iterate through them. So, let's say the following is the data
> > stored
> > in the collection:
> >
> > Key Value
> > ------------
> > AAA Test 1
> > BBB Test 2
> > AAA Test 3
> > BBB Test 4
> > AAA Test 5
> > CCC Test 6
> > DDD Test 7
> > EEE Test 8
> > EEE Test 9
> >
> > I'd like to be able to do this:
> >
> > For Each keyValuePair in keyValuePairCollection.Items
> > Debug.WriteLine("The key is " & keyValuePair.Key & " and the value is[/color][/color]
"[color=blue][color=green]
> > & keyValuePair.Value & ".")
> > keyValuePair.Value = keyValuePair.Value & " has been modified"
> > Debug.WriteLine("The new value is " & keyValuePair.Value & ".")
> > Next
> >
> > The above code would iterate through all 9 key/value pairs and modify
> > their
> > values. I'd also like to be able to do this:
> >
> > For Each keyValuePair in KeyValuePairCollection.FilteredItems("AAA")
> > Debug.WriteLine("The key is " & keyValuePair.Key & " and the value is[/color][/color]
"[color=blue][color=green]
> > & keyValuePair.Value & ".")
> > keyValuePair.Value = keyValuePair.Value & " has been modified"
> > Debug.WriteLine("The new value is " & keyValuePair.Value & ".")
> > Next
> >
> > The above code would iterate through only the 3 key/value pairs with a[/color][/color]
key[color=blue][color=green]
> > of "AAA" and modify their values. So...is all of this possible? Can
> > anyone
> > send me in the right direction? I'd really appreciate any help you can
> > give. Thanks!
> >
> >[/color]
>
>[/color]

re: Implementing a key/value pair collection...with a catch

One additional note...I forgot that you can't change a collection when you
enumerate through it. Ignore that part of my original message where I
showed code modifying the items as I iterated through with For Each. Read
only access should be enough for what I need to do.

"Jeff L." <nospam@nospam.com> wrote in message
news:eeLfBcQ4DHA.416@TK2MSFTNGP10.phx.gbl...[color=blue]
> I think I get what you're saying...the problem is that if I do it that[/color]
way,[color=blue]
> the key/value pairs will no longer be correctly ordered. I need to keep
> them in their original order (which can be any order at all...no specific
> sorting or anything). If I stick them into a hashtable based on their key
> value, they won't be ordered correctly any more.
>
> Jeff
>
> "Ken Tucker [MVP]" <vb2ae@bellsouth.net> wrote in message
> news:Om$UOPQ4DHA.1052@TK2MSFTNGP12.phx.gbl...[color=green]
> > Hi,
> >
> > Here is a suggestion. You store any type of data in a[/color][/color]
hashtable.[color=blue][color=green]
> > Why not store an arraylist with all of your values for each key.
> >
> > Ken
> > -----------------------
> > "Jeff L." <nospam@nospam.com> wrote in message
> > news:%23NATeCQ4DHA.2480@TK2MSFTNGP09.phx.gbl...[color=darkred]
> > >I have an interesting problem and I'm not coming up with any answers in[/color][/color]
> my[color=green][color=darkred]
> > > searches, so hopefully someone can give me a hand with this. I have a
> > > feeling it's easy, but I usually get my nose stuck too far in the[/color][/color]
> details[color=green][color=darkred]
> > > to
> > > see the big picture. :)
> > >
> > > I want to create a collection of key/value pairs. I have a class for[/color][/color]
> the[color=green][color=darkred]
> > > key/value pair...we'll just call it KeyValuePair for this example.[/color][/color][/color]
Now,[color=blue][color=green][color=darkred]
> > > when creating the collection, I need to be able to have duplicate
> > > keys...this is why I can't just use a hashtable. One more requirement[/color][/color]
> is[color=green][color=darkred]
> > > that I can iterate through the entire collection, or just a subset of[/color][/color]
> the[color=green][color=darkred]
> > > collection based on a key. The final requirement is that all[/color][/color][/color]
key/value[color=blue][color=green][color=darkred]
> > > pairs stay in the order that I added them...I can't have them[/color][/color][/color]
rearranged[color=blue][color=green][color=darkred]
> > > when I iterate through them. So, let's say the following is the data
> > > stored
> > > in the collection:
> > >
> > > Key Value
> > > ------------
> > > AAA Test 1
> > > BBB Test 2
> > > AAA Test 3
> > > BBB Test 4
> > > AAA Test 5
> > > CCC Test 6
> > > DDD Test 7
> > > EEE Test 8
> > > EEE Test 9
> > >
> > > I'd like to be able to do this:
> > >
> > > For Each keyValuePair in keyValuePairCollection.Items
> > > Debug.WriteLine("The key is " & keyValuePair.Key & " and the value[/color][/color][/color]
is[color=blue]
> "[color=green][color=darkred]
> > > & keyValuePair.Value & ".")
> > > keyValuePair.Value = keyValuePair.Value & " has been modified"
> > > Debug.WriteLine("The new value is " & keyValuePair.Value & ".")
> > > Next
> > >
> > > The above code would iterate through all 9 key/value pairs and modify
> > > their
> > > values. I'd also like to be able to do this:
> > >
> > > For Each keyValuePair in KeyValuePairCollection.FilteredItems("AAA")
> > > Debug.WriteLine("The key is " & keyValuePair.Key & " and the value[/color][/color][/color]
is[color=blue]
> "[color=green][color=darkred]
> > > & keyValuePair.Value & ".")
> > > keyValuePair.Value = keyValuePair.Value & " has been modified"
> > > Debug.WriteLine("The new value is " & keyValuePair.Value & ".")
> > > Next
> > >
> > > The above code would iterate through only the 3 key/value pairs with a[/color][/color]
> key[color=green][color=darkred]
> > > of "AAA" and modify their values. So...is all of this possible? Can
> > > anyone
> > > send me in the right direction? I'd really appreciate any help you[/color][/color][/color]
can[color=blue][color=green][color=darkred]
> > > give. Thanks!
> > >
> > >[/color]
> >
> >[/color]
>
>[/color]