What are Delegates in C#?

Question:

I have been researching about delegates in C# but the truth is not that clear to me yet.

Can someone explain to me what it is about?

Answer:

A delegate is, in short , a pointer to a function.

That is, imagine that you can create a function and assign it to a variable to pass it as a parameter where you need it. Of course, inheriting all the characteristics of the CLR, including security and strong typing.

msdn:

A delegate is a reference type that can be used to encapsulate a named or anonymous method. Delegates are similar to function pointers in C++, but are safer and provide better type safety.

msdn: Delegates (C# Programming Guide)

A delegate is a type that represents method references with a given parameter list and return type. When a delegate is instantiated, you can attach its instance to any method using a compatible signature and return type. You can invoke (or call) the method through the delegate instance.

Example (msdn)

using System;
public class SamplesDelegate  {

   public delegate String myMethodDelegate( int myInt );

   public class mySampleClass  {

      public String myStringMethod ( int myInt )  {
         if ( myInt > 0 )
            return( "positive" );
         if ( myInt < 0 )
            return( "negative" );
         return ( "zero" );
      }

      public static String mySignMethod ( int myInt )  {
         if ( myInt > 0 )
            return( "+" );
         if ( myInt < 0 )
            return( "-" );
         return ( "" );
      }
   }

   public static void Main()  {

      mySampleClass mySC = new mySampleClass();

      myMethodDelegate myD1 = new myMethodDelegate( mySC.myStringMethod );
      myMethodDelegate myD2 = new myMethodDelegate( mySampleClass.mySignMethod );


      Console.WriteLine( "{0} is {1}; use the sign \"{2}\".", 5, myD1( 5 ), myD2( 5 ) );
      Console.WriteLine( "{0} is {1}; use the sign \"{2}\".", -3, myD1( -3 ), myD2( -3 ) );
      Console.WriteLine( "{0} is {1}; use the sign \"{2}\".", 0, myD1( 0 ), myD2( 0 ) );
   }

}


/*
This code produces the following output:

5 is positive; use the sign "+".
-3 is negative; use the sign "-".
0 is zero; use the sign "".
*/