What are sealed modifiers in C#?

When you use sealed modifiers in C# on a method, then the method loses its capabilities of overriding. The sealed method should be part of a derived class and the method must be an overridden method.

Let us see an example −

The following example won’t allow you to override the method display() because it has a sealed modifier for the ClassTwo derived class −

ClassOne is our base class, whereas ClassTwo and ClassThree are derived classes −

Example

class ClassOne {
   public virtual void display() {
      Console.WriteLine("baseclass");
   }
}

class ClassTwo : ClassOne {
   public sealed override void display() {
      Console.WriteLine("ClassTwoderivedClass");
   }
}

class ClassThree : ClassTwo {
   public override void display() {
      Console.WriteLine("ClassThree: Another Derived Class");
   }
}

Above, under ClassThree derived class we have tried to override the sealed method. This will show an error since it is not allowed when you use the sealed method.