1. What’s New in C# 4.0 Abed El-Azeem Bukhari (MCPD,MCTS,MCP) el-bukhari.com

2. private int test; public int Test { get { return test } set { test = value; } } public int MyProperty { get; set; } Short-form Properties What’s new in C# 3.5?

3. Object and collection Initialize public class MyStructure { public int MyProperty1 { get; set; } public int MyProperty2 { get; set; } } MyStructure myStructure = new MyStructure() { MyProperty1 = 5, MyProperty2 = 10 }; List < int > myInts = new List < int > () { 5, 10, 15, 20, 25 }; What’s new in C# 3.5?

4. What’s new in C# 4.0 public void Myfunction( string param1 =“flykit&quot; , bool param2 = false , int param3 = 24 ) { } As VB.NET, You can put default values for the parameters. Optional Parameters

5. Named Parameters Myfunction(“najah&quot;,50); // Error ! Myfunction(“najah&quot;,param3: 50); public void Myfunction( string param1 =“flykit&quot; , bool param2 = false , int param3 = 24 ) { }

6. COM interop ((Excel.Range)excel.Cells[1, 1]).Value = “Hiiiiiiiii&quot;; excel.Cells[1, 1].Value = &quot;Hiiiiiiiii&quot;;

7. Variance IList<string> strings = new List<string>(); IList<object> objects = strings;// Error IEnumerable<object> objects = strings;

8. Dynamic Programming object calculator = GetCalculator(); Type calculatorType = calculator.GetType(); object res = calculatorType.InvokeMember(&quot;Add&quot;, BindingFlags.InvokeMethod, null, calculator, new object[] { 10, 20 }); int sum = Convert.ToInt32(res); And what if the calculator was a JavaScript object? ScriptObject calculator = GetCalculator(); object res = calculator.Invoke(&quot;Add&quot;, 10, 20); int sum = Convert.ToInt32(res); For each dynamic domain we have a different programming experience and that makes it very hard to unify the code. With C# 4.0 it becomes possible to write code this way: dynamic calculator = GetCalculator(); int sum = calculator.Add(10, 20);

9. Dynamic Programming cont. dynamic x = 1; dynamic y = &quot;Hello&quot;; dynamic z = new List<int> { 1, 2, 3 }; Code Resolution Method double x = 1.75; double y = Math .Abs(x); compile-time double Abs(double x) dynamic x = 1.75; dynamic y = Math .Abs(x); run-time double Abs(double x) dynamic x = 2; dynamic y = Math .Abs(x); run-time int Abs(int x)

10. Diffrence between var and dynamic keyword: string s = “We are DotNet Students&quot;; var test = s; Console.WriteLine (test.MethodDoesnotExist());// Error 'string' does not contain a definition for 'MethodDoesnotExist' and no extension method 'MethodDoesnotExist' string s = “We are DotNet Students&quot;; dynamic test = s; Console.WriteLine (test.MethodDoesnotExist());// OK! Used for programming with COM or JavaScript which can have runtime properties!!

11. System.Tuple var squaresList = System.Tuple.Create(1, 4, 9, 16, 25, 36, 49, 64); Console.WriteLine(&quot;1st item: {0}&quot;, squaresList.Item1); //1 Console.WriteLine(&quot;4th item: {0}&quot;, squaresList.Item4); //16 Console.WriteLine(&quot;8th item: {0}&quot;, squaresList.Rest); //(64) Console.ReadKey(); Console.WriteLine(Environment.NewLine);

12. System.Tuple cont. var tupleWithMoreThan8Elements = System.Tuple.Create(&quot; is&quot;, 2.3, 4.0f, new List<CHAR> { 'e', 't', 'h' }, “najah dotnet&quot;, new Stack<INT>(4), &quot;best&quot;, squaresList); // we'll sort the list of chars in descending order tupleWithMoreThan8Elements.Item4.Sort(); tupleWithMoreThan8Elements.Item4.Reverse(); Console.WriteLine(&quot;{0} {1} {2} {3}&quot;, tupleWithMoreThan8Elements.Item5, tupleWithMoreThan8Elements.Item1, string.Concat(tupleWithMoreThan8Elements.Item4), tupleWithMoreThan8Elements.Item7); // najah dotnet is the best Console.WriteLine(&quot;Rest: {0}&quot;, tupleWithMoreThan8Elements.Rest); Console.WriteLine(&quot;Rest's 2nd element: {0}&quot;, tupleWithMoreThan8Elements.Rest.Item1.Item2); Console.WriteLine(&quot;Rest's 5th element: {0}&quot;, tupleWithMoreThan8Elements.Rest.Item1.Item5); Console.ReadKey(); Output : Rest: ((1, 4, 9, 16, 25, 36, 49, 64)) Rest's 2nd element: 4 Rest's 5th element: 25

13. System.Numerics Complex numbers static void Main(string[] args) { var z1 = new Complex(); // this creates complex zero (0, 0) var z2 = new Complex(2, 4); var z3 = new Complex(3, 5); Console.WriteLine(&quot;Complex zero: &quot; + z1); Console.WriteLine(z2 + &quot; + &quot; + z3 + &quot; = &quot; + (z2 + z3)); Console.WriteLine(&quot;|z2| = &quot; + z2.Magnitude); Console.WriteLine(&quot;Phase of z2 = &quot; + z2.Phase); Console.ReadLine(); } Complex zero: (0, 0) (2, 4) + (3, 5) = (5, 9) |z2| = 4,47213595499958 Phase of z2 = 1,10714871779409 Output

14. System.Numerics Complex numbers cont. static void Main(string[] args) { var z2 = new Complex(2, 4); var z3 = new Complex(3, 5); var z4 = Complex.Add(z2, z3); var z5 = Complex.Subtract(z2, z3); var z6 = Complex.Multiply(z2, z3); var z7 = Complex.Divide(z2, z3); Console.WriteLine(&quot;z2 + z3 = &quot; + z4); Console.WriteLine(&quot;z2 - z3 = &quot; + z5); Console.WriteLine(&quot;z2 * z3 = &quot; + z6); Console.WriteLine(&quot;z2 / z3 = &quot; + z7); Console.ReadLine(); } Output z2 + z3 = (5, 9) z2 - z3 = (-1, -1) z2 * z3 = (-14, 22) z2 / z3 = (0,76470588235, 0,058823529411)

15. Parallel Programming

18. Parallel Programming For Loop using System.Threading.Tasks ; .. //serial implementation for (int i = 0; i < 10; i++) { //Do stuff .. anything } //parallel implementation Parallel.For(0, 10, i => { /*anything with i*/ } );

19. Parallel Programming PLINQ bool[] results = new bool[arr.Length]; // arr is array of integers for (int i = 0; i < arr.Length; i++) { results[i] = IsPrime(arr[i]); } //LINQ to Objects bool[] results1 = arr.Select(x => IsPrime(x)) .ToArray(); //PLINQ bool[] results2 = arr.AsParallel().Select(x => IsPrime(x)) .ToArray();

20. Parallel Tasks (Debug Menu -> Windows -> Parallel Tasks):

21. thread-safe-data-structures Queue : ConcurrentQueue<T> ConcurrentQueue<int> queue = new ConcurrentQueue<int>(); queue.Enqueue(10); int t; Console.WriteLine(queue.TryPeek(out t)); Console.WriteLine(queue.TryDequeue(out t));

22. thread-safe-data-structures cont. Stack : ConcurrentStack<T> ConcurrentStack<int> stack = new ConcurrentStack<int>(); stack.Push(10); stack.PushRange(new int[] { 1, 2, 3, 4, 5 }); int t; if (stack.TryPop(out t)){ Console.WriteLine(&quot;Pop: &quot; + t);} if (stack.TryPeek(out t)){ Console.WriteLine(&quot;Peek: &quot; + t);} int[] ts = new int[5]; int count; if ((count = stack.TryPopRange(ts, 0, 3)) > 0){ Console.WriteLine(&quot;PopRange&quot;); for (int i = 0; i < count; i++) { Console.WriteLine(ts[i]); }}

23. thread-safe-data-structures cont. Collection : ConcurrentBag<T> ConcurrentBag<int> bag = new ConcurrentBag<int>(new int[] { 1, 1, 2, 3 }); bag.Add(70); int t; bag.TryPeek(out t); Console.WriteLine(t); bag.Add(110); Console.WriteLine(); for (int i = 0; i < 3; i++){ bag.TryTake(out t); Console.WriteLine(t);}

26. Thanks for Attending Abed El-Azeem Bukhari (MCPD,MCTS,MCP) el-bukhari.com