Private and final methods in C#

Private Methods

To set private methods, use the private access specifier.

Private access specifier allows a class to hide its member variables and member functions from other functions and objects. Only functions of the same class can access its private members. Even an instance of a class cannot access its private members.

Final Methods

For final methods, use the sealed modifier.

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("ClassTwo: DerivedClass");
   }
}

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.