how to initialize dictionary as (key,value,value) pair in C#

Question

I want to store values as key,value,value pair. My data is of type

Key -> int & both values -> ulong,

How to initialize & fetch values of such dictionary. I am using VS-2005.

If i use a class or struct then how do i fetch the values.

Answer 1

maybe you have to define a class say class Pair to hold your two value, and use int as the key.

Answer 2

You can declare a class that stores both values and then use an ordinary dictionary. For example:

class Values {
    ulong Value1 {get;set;}
    ulong Value2 {get;set;}
}

var theDictionary=new Dictionary<int, Values>;

theDictionary.Add(1, new Values {Value1=2, Value2=3});

Answer 3

This would be an option:

Dictionary<int, KeyValuePair<ulong, ulong>> dictionary = new Dictionary<int, KeyValuePair<ulong, ulong>>();

If you want to add in a value: Key=1, Pair = {2,3}

dictionary.Add(1, new KeyValuePair<ulong, ulong>(2, 3));

If you want to retrieve those values:

var valuePair = dictionary[1];
ulong value1 = valuePair.Key;
ulong value2 = valuePair.Value;

Or simply:

ulong value1 = dictionary[1].Key;

Answer 4

I'm not sure I understand your question correctly, but if you want to store more than one value in the value part of Dictionary, you could do something like this:

var dic = new Dictionary<int,KeyValuePair<ulong,ulong>>();

You can use insert into the dictionary like this:

dic.Add(42, new KeyValuePair<ulong, ulong>(42, 42));
dic.Add(43, new KeyValuePair<ulong, ulong>(43, 43));

And fetch the values like so:

foreach (var a in dic)
{
    Console.WriteLine("Key: {0}, Value1: {1}, Value2: {2}",
        a.Key, a.Value.Key, a.Value.Value);
}

Answer 5

You can make use of the KeyValuePair

Dictionary<int, KeyValuePair<ulong,ulong>> vals = new Dictionary<int, KeyValuePair<ulong, ulong>>();

Answer 6

Create a structure to store your values:

struct ValuePair
{
    public ulong Value1;
    public ulong Value2;
}

Dictionary initialization:

Dictionary<int, ValuePair> dictionary = new Dictionary<int, ValuePair>();

Maybe List is enogh, if you use int as key?

List:

List<ValuePair> list = new List<ValuePair>();

Answer 7

Look at Wintellect.PowerCollections Namespace they have special structure Pair<(Of ) and collections to work with it or you'll need to code your own Pair type.

Answer 8

Create a Tuple class, in the System namespace:

public class Tuple<T1,T2>
{
    private readonly T1 _item1;
    private readonly T2 _item2;

    public Tuple(T1 item1, T2 item2)
    {
        this._item1 = item1;
        this._item2 = item2;
    }

    public T1 Item1 { get { return _item1; } }

    public T2 Item2 { get { return _item2; } }
}

And a static Tuple class with a Create method so you get type inference which is not available on constructors:

public static class Tuple
{
    public static Tuple<T1, T2> Create<T1, T2>(T1 item1, T2 item2)
    {
        return new Tuple<T1, T2>(item1, item2);
    }
}

Then, when you get onto .NET 4.0, you can delete these classes because they're in the Base Class Library (and are compatible with F# tuples!).

Answer 9

In C# 4, you'll have the Tuple type for your value, value pair.

There's an MSDN article describing the type and the design decisions behind it.