C# Programming/Keywords/base

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The keyword base describes that you would like to refer to the base class for the requested information, not in the current instantiated class.

A base class is the class in which the currently implemented class inherits from. When creating a class with no defined base class, the compiler automatically uses the System.Object base class.

Therefore the two declarations below are equivalent.

public class MyClass

public class MyClass : System.Object

Some of the reasons the base keyword is used is:

  • Passing information to the base class's constructor
public class MyCustomException : System.Exception
     public MyCustomException() : base() {}

     public MyCustomerException(string message, Exception innerException) : base(message,innerException) {}

     // ......
  • Recalling variables in the base class, where the newly implemented class is overriding its behaviour
public class MyBaseClass
     protected string className = "MyBaseClass";

public class MyNewClass : MyBaseClass
     protected new string className = "MyNewClass";

     public override string BaseClassName
          get { return base.className; }
  • Recalling methods in the base class. This is useful when you want to add to a method, but still keep the underlying implementation.
// Necessary using's here

public class _Default : System.Web.UI.Page
     protected void InitializeCulture()
          System.Threading.Thread.CurrentThread.CurrentUICulture =


C# Keywords
abstract as base bool break
byte case catch char checked
class const continue decimal default
delegate do double else enum
event explicit extern false finally
fixed float for foreach
goto if implicit in int
interface internal is lock long
namespace new null object operator
out override params private protected
public readonly ref return sbyte
sealed short sizeof stackalloc
static string struct switch this
throw true try typeof uint
ulong unchecked unsafe ushort using
var virtual void volatile while
Special C# Identifiers
add alias get global partial
remove set value where yield