Conversion Operators

ToArray

This sample uses ToArray to immediately evaluate a sequence into an array.

Code:

            public void Linq54()
            {
                double[] doubles = { 1.7, 2.3, 1.9, 4.1, 2.9 };

                var sortedDoubles = doubles.OrderByDescending(d => d);
                var doublesArray = sortedDoubles.ToArray();

                Log.WriteLine("Every other double from highest to lowest:");
                for (int d = 0; d < doublesArray.Length; d += 2)
                {
                    Log.WriteLine(doublesArray[d]);
                }
            }

Result:

ToList

This sample uses ToList to immediately evaluate a sequence into a List.

Code:

            public void Linq55()
            {
                string[] words = { "cherry", "apple", "blueberry" };

                var sortedWords =
                    from w in words
                    orderby w
                    select w;
                var wordList = sortedWords.ToList();

                Log.WriteLine("The sorted word list:");
                foreach (var w in wordList)
                {
                    Log.WriteLine(w);
                }
            }

Result:

ToDictionary

This sample uses ToDictionary to immediately evaluate a sequence and a related key expression into a dictionary.

Code:

            public void Linq56()
            {
                var scoreRecords = new[] { 
                    new {Name = "Alice", Score = 50},
                    new {Name = "Bob"  , Score = 40},
                    new {Name = "Cathy", Score = 45}
                };

                var scoreRecordsDict = scoreRecords.ToDictionary(sr => sr.Name);

                Log.WriteLine("Bob's score: {0}", scoreRecordsDict["Bob"]);
            }

Result:

OfType

This sample uses OfType to return only the elements of the array that are of type double.

Code:

            public void Linq57()
            {
                object[] numbers = { null, 1.0, "two", 3, "four", 5, "six", 7.0 };

                var doubles = numbers.OfType();

                Log.WriteLine("Numbers stored as doubles:");
                foreach (var d in doubles)
                {
                    Log.WriteLine(d);
                }
            }