C# Making a new list by combining two lists together

Question

So I am trying to find how to best make a list that will combine two lists of equal size of two different types together, in a way so that the indexes will be the same. How can i do this?

var list = new List<KeyValuePair<List<Card>, List<Card>>>();
list.AddRange(new List<KeyValuePair<List<Card>,List<Card>>>(_listCards,cloneOf_listCards));

The code above has been my way of trying to get it to work where Card is a class with both Suit and Cardnumber. though my code doesn't do it i wish to make it a list with Images instead of Card for one list. I have already seen these and many other threads: join of two lists in c# https://stackoverflow.com/questions/16465804/return-two-combined-listt

Answer 1

You could use the Enumerable.Zip extension method.

For example:

_listCards.Zip(cloneOf_listCards, (cardA, cardB) => new KeyValuePair<Card, Card>(cardA, cardB));

Granted, this will give you a single List<KeyValuePair<Card,Card>> instead of a KeyValuePair<List<Card>, List<Card>> , but I'd argue that's a better design anyways.

At that point (if you so desire), you can probably just turn it into a Dictionary<Card,Card> :

var joined = _listCards.Zip(cloneOf_listCards, (cardA, cardB) => new KeyValuePair<Card, Card>(cardA, cardB));
var dictionary = joined.ToDictionary(kv => kv.Key, kv => kv.Value);

Note that if your lists are of different sizes, Enumerable.Zip will only join the elements up to the end of the shorter list and then stop.