all extension methods in c# code example

Example 1: define extension methods c#

public static class MyExtensions
{
  //use the this keyword before an argument
  public static int WordCount(this String str)
  {
    return str.Split(new char[] { ' ', '.', '?' },
                     StringSplitOptions.RemoveEmptyEntries).Length;
  }
}

Example 2: c# method info extension

private static readonly MethodInfo ExtensionMethod = 
  typeof(ObjectExtensions).GetMethod(nameof(ObjectExtensions.NewMethod));