我该如何使用Linq？

Question

Imagine I have the following arrays:

int[] player = new int[5] { 1, 2, 3, 4, 4 };
int[] computer = new int[5] { 1, 1, 1, 3, 5 };

How can I use a Linq query to fetch the amount of times each number is in each collection?

Answer 1

This would give you the frequency of each number in the player array, same would work for the computer array:

var playerFrequencies = player.GroupBy(n => n)
                              .Select(g => new { Number = g.Key, 
                                                Frequency = g.Count() })
                              .ToList();

Answer 2

var count =
    from i in player
    group i by i into g
    select new { Number = g.Key, Count = g.Count() }

Answer 3

  int HowManyTimes(IEnumerable<int> numberCollection, int numberToFind){
        return numberCollection.Count(x = >x == numberToFind);
  }