Guy Ellis Rocks

The problem: You have a classic Hashtable. Although the keys are strings they hold only ints. You also have a list of ints. You want to find out if any of the keys from the Hashtable are in the list of ints. How do you do this in one line of LINQ?

The solution, using LINQ, that I came up with is:

            // Setup the test data
            System.Collections.Hashtable ht = new System.Collections.Hashtable();
            ht.Add("1", new object());
            ht.Add("2", new object());

            List<int> second = new List<int>();
            second.Add(2);
            second.Add(3);

            // Query the data
            bool containsKey = ht.Keys.Cast<string>().Select(a => Convert.ToInt32(a)).ToList().Intersect(second).Count() > 0;

            // Print the result
            Console.Write("Contains Key: {0}", containsKey);