Uses of Action delegate in C# [closed]

by

Here is a small example that shows the usefulness of the Action delegate

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        Action<String> print = new Action<String>(Program.Print);

        List<String> names = new List<String> { "andrew", "nicole" };

        names.ForEach(print);

        Console.Read();
    }

    static void Print(String s)
    {
        Console.WriteLine(s);
    }
}

Notice that the foreach method iterates the collection of names and executes the print method against each member of the collection. This a bit of a paradigm shift for us C# developers as we move towards a more functional style of programming. (For more info on the computer science behind it read this: http://en.wikipedia.org/wiki/Map_(higher-order_function).

Now if you are using C# 3 you can slick this up a bit with a lambda expression like so:

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<String> names = new List<String> { "andrew", "nicole" };

        names.ForEach(s => Console.WriteLine(s));

        Console.Read();
    }
}

More Related Contents:

  1. Why would you use Expression rather than Func?
  2. delegate keyword vs. lambda notation
  3. Why can’t an anonymous method be assigned to var?
  4. Func vs. Action vs. Predicate [duplicate]
  5. Why must a lambda expression be cast when supplied as a plain Delegate parameter
  6. How do I invoke an extension method using reflection?
  7. Creating delegates manually vs using Action/Func delegates
  8. Wrapping StopWatch timing with a delegate or lambda?
  9. What’s the point of a lambda expression?
  10. Creating a property setter delegate
  11. Get All instead of FirstOrDefault
  12. Invoke(Delegate)
  13. When & why to use delegates? [duplicate]
  14. C#: Difference between ‘ += anEvent’ and ‘ += new EventHandler(anEvent)’
  15. How do I Unregister ‘anonymous’ event handler [duplicate]
  16. Lambda variable capture in loop – what happens here? [duplicate]
  17. Multiple Order By with LINQ [duplicate]
  18. What are C# lambda’s compiled into? A stackframe, an instance of an anonymous type, or?
  19. Are C# events synchronous?
  20. Fastest way to Remove Duplicate Value from a list by lambda
  21. Why does asynchronous delegate method require calling EndInvoke?
  22. How to merge a list of lists with same type of items to a single list of items?
  23. Func delegate with ref variable
  24. What are the advantages of delegates? [duplicate]
  25. Discrete Anonymous methods sharing a class?
  26. Is there a way to specify an “empty” C# lambda expression?
  27. C# – How can I “overload” a delegate?
  28. Lambda Expression for join
  29. Can someone distill into proper English what a delegate is?
  30. Reflection Performance – Create Delegate (Properties C#)

Leave a Comment