Question

I currently have a dictionary that loads up with data on the start of the program and its something like:

  Dictionary<string, List<KeyValuePair<string,string>>> variants =
    new Dictionary<string, List<KeyValuePair<string, string>>>();

How would i reference it if i want to access the Keyvaluepair list of a specific string…

here’s an understanding of it:
each list has an identifier (which is the string) –> the string leads to a list of Keyvaluepairs,
and i want to chose them randomly

Answer 1

Let’s break it down:

// This is your dictionary.
Dictionary<string, List<KeyValuePair<string,string>>> variants = new Dictionary<string, List<KeyValuePair<string, string>>>();

// Let's get the list of variants for a given key.
string key = "myKey";
List<KeyValuePair<string,string>> variantsForKey = variants[key];

// If we wanted to get the first variant, we'd use one of these:
KeyValuePair<string,string> firstVariant = variantsForKey[0];
firstVariant = variantsForKey.First(); // Using Linq for fun and profit!

// Now, we want a random variant? No problem!
Random rand = new Random(); // Remember to initialize this only once!
int listLength = variantsForKey.Count;
int randomVariantIndex = rand.Next(0, listLength );
KeyValuePair<string,string> randomVariant = variantsForKey[randomVariantIndex];

Voila!

Now, what you might want to do is wrap those last 3 lines in an extension method:

public static class VariantExtensions
{
    private static Random rand = new Random();
    public static KeyValuePair<string,string> GetRandomVariant(this List<KeyValuePair<string,string>> variantsForKey)
    {
         int listLength = variantsForKey.Count;
         int randomVariantIndex = rand.Next(0, listLength );
         return variantsForKey[randomVariantIndex];
    }
}

and now you can use this:

Dictionary<string, List<KeyValuePair<string,string>>> variants = ...;
string key = "myKey";
KeyValuePair<string,string> randomVariant = variants[key].GetRandomVariant();