generics and this keyword in argument list

  • Thread starter Thread starter puzzlecracker
  • Start date Start date
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puzzlecracker

In the example below ( it's taken off Jon's blogs), what does this
keyword in the parameter list mean?
Also, why do we need to do specify generic T here WithLogging<T>?
wouldn't type be derived from IEnumerable<T> ?


using System;
using System.Collections.Generic;

public static class Extensions
{
public static IEnumerable<T> WithLogging<T>(this IEnumerable<T>
source,
string name)
{
foreach (T element in source)
{
Console.WriteLine("{0}: {1}", name, element);
yield return element;
}
}
}
 
puzzlecracker said:
In the example below ( it's taken off Jon's blogs), what does this
keyword in the parameter list mean?
Also, why do we need to do specify generic T here WithLogging<T>?
wouldn't type be derived from IEnumerable<T> ?


using System;
using System.Collections.Generic;

public static class Extensions
{
public static IEnumerable<T> WithLogging<T>(this IEnumerable<T>
source,
string name)
Click to expand...

It is a static class with a static method using 'this' on the first
argument to define an extension method. So using C# or VB.NET 2008 you
can call a method WithLogging on any IEnumerable<T>.
See http://msdn.microsoft.com/en-us/library/bb383977.aspx for an
introduction to extension methods.
 
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