C# 3.0 Language Extensions

Put together a little snippet to remind myself of the some of the beautiful language extensions that shipped with the C# language.

{% highlight csharp %} namespace CSharpLanguageExperiment { using System; using System.Collections.Generic; using System.Linq;

class Program { static void Main(string[] args) { // Object Initialiser Person bill = new Person { FirstName = “Bill”, LastName = “Gates”, Age = 40 };

  // Type Inference
  var ben = new Person { FirstName = "Ben", LastName = "Simmonds", Age = 25 }; 

  // Anonymous Types
  var john = new { FirstName = "John", LastName = "Smith", Age = 18 }; 

  // Anonymous Delegate
  Func<string, bool> filter1 = delegate(string name)
  {
    return name.Length > 4;
  };
  filter1("hel"); 

  // Lambda Expression
  Func<string, bool> filter2 = x => x.Length > 4;
  filter2("foobar"); 

  // Extension Method
  ben.GetData(); 

  // Queries
  List<Person> people = new List<Person>();
  people.Add(bill);
  people.Add(ben);
  Func<Person, bool> filter = x => x.Age > 30;
  IEnumerable<Person> exp = people.Where(filter); 

  foreach (Person person in exp)
  {
    Console.WriteLine(person.GetData());
  }
}

}

public class Person { public string FirstName { get; set; } public string LastName { get; set; } public int Age { get; set; }

public override string ToString()
{
  return String.Format("{0} {1}",
    FirstName,
    LastName);
}

}

// Extension Method public static class PersonExtension { public static string GetData(this Person person) { return String.Format(“Name: {0} {1} Age: {2}”, person.FirstName, person.LastName, person.Age); } } } {% endhighlight %}