To/From Code

	Languages
BROWSEBYLANGUAGE Access VBA ASP Classic C# C++ C++/CLI Corel Paradox Delphi Delphi Prism Java JavaScript Perl PHP VB Classic VB.Net

	Categories
BROWSEBYCATEGORY +Tool Basics +Language Basics +Language Details +Data Structures +Statements +Operators +Commands +Database +OOP Basics +OOP Details

	C# Guides
C# To/From Conversion Guides C# and Access VBA C# and ASP Classic C# and C++ C# and C++/CLI C# and Corel Paradox C# and Delphi C# and Delphi Prism C# and Java C# and Perl C# and PHP C# and VB Classic C# and VB.Net

Cross Ref Guide

C#LANGUAGE

C#ANDJAVASCRIPTTOC

Overview

+Tool Basics

Report Tools Overview

+Language Basics

+Language Details

+Data Structures

+Statements

+Operators

+Commands

+OOP Basics

+OOP Details

Prevent Derivation◄╣

	Members-Only
Sign in to see member-only pages.

► KB ► To/From Guides ► C#

Print This

Prevent Derivation (C# and JavaScript Cross Reference Guide)

By Mike Prestwood

C# versus JavaScript: A side by side comparison between C# and JavaScript.

OOP Details

More object oriented (OO) stuff.

Prevent Derivation

[Other Languages]

Languages Focus

How do you prevent another class from inheriting and/or prevent a class from overriding a member.

C#: sealed

With C#, use the sealed keyword to prevent a class from being inherited from and to prevent a method from being overridden.

A method marked sealed must override an ancestor method. If you mark a class sealed, all members are implicitly not overridable so the sealed keyword on members is not legal.

Syntax Example:

public class Machine : System.Object
{
  public virtual void Speak(String pSentence)
  {
    MessageBox.Show(pSentence);
  }
}
    
public class Robot : Machine
{
  public sealed override void Speak(String pSentence)
  {
    MessageBox.Show(pSentence);
  }
}

public sealed class Cyborg : Robot
{ 
}

[Not specified yet. Coming...]