is there a <key, value, value> dictionaryish type in C#?

Question

I need something resembling the following:

Dictionary<string, List<int>, List<DateTime>> = new Dictionary<string, List<int>, List<DateTime>>()

are there any built in class in C# which offer something like the above?

Edit: for people who can't see why anything like this could ever possibly be useful...

Imagine if you could write something like this:

mySuperDictionary SuperDictionary<string, List<int>X, List<int>Y> ..... myXvalues = mySuperDictionary["myKey"].X; myYvalues = mySuperDictionary["myKey"].Y;

personally I think that would be a pretty neat.

how about putting the int and the DateTime in a struct/class? — kenny
– kenny, Commented Jan 5, 2010 at 17:33
How exactly is this meant to be used? I cannot even theorize a situation where this would be useful. Perhaps you want to lookup an int and datetime for each string.. yes? — Chris Kannon
– Chris Kannon, Commented Jan 5, 2010 at 17:34
Posting the code you want to compile is not very helpful. Tell us what behavior you want out of such a data structure. — R. Martinho Fernandes
– R. Martinho Fernandes, Commented Jan 5, 2010 at 17:39

Kevin Montrose · Accepted Answer · 2010-01-05 17:34:01Z

26

No.

Create a Pair or Tuple type yourself.

Something like:

class Pair<T,V> { T First{get; set;} V Second{get; set;} }

Then you can declare a Dictionary<string, Pair<List<int>, List<DateTime>>.

answered Jan 5, 2010 at 17:34

Kevin Montrose

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2 Comments

Kevin Montrose Over a year ago

Its worth noting that in .NET 4.0 there is/will be a Tuple type. So this answer will be out of date shortly for those of us on the cutting edge.

Andreas Grech Over a year ago

stackoverflow.com/questions/152019/…

Brandon · Accepted Answer · 2010-01-05 17:33:57Z

I do not believe so. I think it would be better if you made a custom object to hold your List<int> and List<DateTime> objects.

Dictionary<string, CustomClass>> = new Dictionary<string, CustomClass>(); public class CustomClass { public List<int> IntegerList { get; set; } public List<DateTime> DateTimeList { get; set; } }

Reed Copsey · Accepted Answer · 2010-01-05 17:34:53Z

Normally, you'd just do:

Dictionary<string, KeyValuePair<List<int>,List<DateTime>>> dictionary;

A custom class is usaully nicer, however, for this type of thing. Having Dictionary<Key, Value, Value> doesn't really add any value - it's still a single key -> something lookup, so just make your value handle it.

Ravi Vanapalli · Accepted Answer · 2010-01-05 17:34:05Z

0

There are not built in class as your requirement but you can create your own.

answered Jan 5, 2010 at 17:34

Ravi Vanapalli

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Comments

Community · Accepted Answer · 2017-05-23 11:55:19Z

No, you'll have to roll your own. This could be easily done with a simple struct or class. This answer has good information on how to do something like this using tuples.

Grant Palin · Accepted Answer · 2010-01-05 17:36:04Z

0

I think there is a generic Pair<> class in the framework, which you could use to associate two "values" with each other.

answered Jan 5, 2010 at 17:36

Grant Palin

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3 Comments

R. Martinho Fernandes Over a year ago

There is KeyValuePair2` in .NET 2.0, but it is ugly because it has a very long name and it has other meanings associated with it. In .NET 4.0 there's the series of Tuple classes.

Grant Palin Over a year ago

Duly noted. I've used the KeyValuePair previously; it is a bit clunky, and has a certain implied meaning, besides just "Pair". I'll see what I can find about the Tuple you mentioned.

Benjol Over a year ago

rolling your own Tuple is trivial.

cethie · Accepted Answer · 2010-01-05 18:23:33Z

Strongly typed datatable could produce the same data (and structure) you need. See below.

http://www.codeproject.com/KB/database/TypedDataTable.aspx

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