how can I create a hash of hash (or key with multiple values)

[digitech]

Hi,

In perl I can create a hash of hash which would have something like

$MYHASH{'USER1'}{'SPORT'}{'FOOTBALL'} =1

$MYHASH{'USER1'}{'SPORT'}{'TENNIS'} =1

http://docstore.mik.ua/orelly/perl/prog3/ch09_04.htm shows a type of example on the perl page.

This way I can loop through the users and the sports and find out what sports they are associated to.

How can I create a similar stucture in c Sharp, I have been looking at hashtables but they only show my key <=> values. Where I need to have a key with an array of values that I can index in on.

Can anyone help here please or point me to some examples ?

Thanks in advance.

[PRR]

If you are looking for collection that allows multiple values per key then you can go in for NameValueCollection

NameValueCollection mycol = new NameValueCollection();
            mycol.Add("1", "1");
            mycol.Add("1", "2");
            mycol.Add("1", "3");
            mycol.Add("1", "4");
 
            foreach (string s in mycol.GetValues(0))
            {
                Console.WriteLine(mycol[s]);
            }
 

[digitech]

Thanks this is great, I noticed on the link that NameValueCollection is for 2008 only is there an eqilavant way of doing this for VS 2005 ?

[vekipeki]

It exists in VS2005 also: NameValueCollection.

But Hashtable also implements IEnumerable for DictionaryEntry objects, so you can also write:

foreach (DictionaryEntry entry in myHashtable)
{
   Console.WriteLine("Key = {0}, Value = {1}", entry.Key, entry.Value);
}

There is also a generic Dictionary<TKey,TValue> you can use, which implements IEnumerable for KeyValuePair<TKey,TValue> items.