How can you prevent inheritance from a class in C#.NET?

1. Inheritance
2. Encapsulation
3. Templates
4. Containership
5. Polymorphism

namespace CuriousTabConsoleApplication
{ 
    class Baseclass
    { 
        public void fun()
        { 
            Console.Write("Base class" + " ");
        } 
    } 
    class Derived1: Baseclass
    { 
        new void fun()
        {
            Console.Write("Derived1 class" + " "); 
        } 
    } 
    class Derived2: Derived1
    { 
        new void fun()
        { 
            Console.Write("Derived2 class" + " ");
        }
    }
    class Program
    { 
        public static void Main(string[ ] args)
        { 
            Derived2 d = new Derived2(); 
            d.fun(); 
        } 
    } 
}

namespace CuriousTabConsoleApplication
{ 
    class Sample
    { 
        int i; 
        Single j; 
        public void SetData(int i, Single j)
        { 
            i = i;
            j = j;
        }
        public void Display()
        { 
            Console.WriteLine(i + " " + j);
        } 
    } 
    class MyProgram
    { 
        static void Main(string[ ] args)
        { 
            Sample s1 = new Sample();
            s1.SetData(10, 5.4f); 
            s1.Display(); 
        } 
    } 
}

1. this reference can be modified in the instance member function of a class.
2. Static functions of a class never receive the this reference.
3. Instance member functions of a class always receive a this reference.
4. this reference continues to exist even after control returns from an instance member function.
5. While calling an instance member function we are not required to pass the this reference explicitly.

1. Instance members of a class can be accessed only through an object of that class.
2. A class can contain only instance data and instance member function.
3. All objects created from a class will occupy equal number of bytes in memory.
4. A class can contain Friend functions.
5. A class is a blueprint or a template according to which objects are created.

class BaseClass
{
    protected int i = 13;
}
class Derived: BaseClass
{
    int i = 9; 
    public void fun()
    {
        // [*** Add statement here ***]
    } 
}

namespace CuriousTabConsoleApplication
{ 
    class A
    {
        public void fun()
        {
            Console.Write("Welcome");
        } 
    } 
    class B: A
    {
        public void fun()
        {
            // [*** Add statement here ***]
            Console.WriteLine(" to CuriousTab.com!");
        } 
    } 
    class MyProgram
    { 
        static void Main (string[ ] args)
        { 
            B b = new B(); 
            b.fun();
        } 
    } 
}

namespace CuriousTabConsoleApplication
{ 
    class index
    {
        protected int count;
        public index()
        {
            count = 0;
        }
    }
    class index1: index
    {
        public void increment()
        {
            count = count +1;
        }
    }
    class MyProgram
    {
        static void Main(string[] args)
        {
            index1 i = new index1(); 
            i.increment(); 
        }
    }
}

1. count should be declared as public if it is to become available in the inheritance chain.
2. count should be declared as protected if it is to become available in the inheritance chain.
3. While constructing an object referred to by i firstly constructor of index class will be called followed by constructor of index1 class.
4. Constructor of index class does not get inherited in index1 class.
5. count should be declared as Friend if it is to become available in the inheritance chain.

namespace CuriousTabConsoleApplication
{ 
    class Baseclass
    {
        private int i; 
        protected int j; 
        public int k;
    }
    class Derived: Baseclass
    {
        private int x; 
        protected int y; 
        public int z;
    }
    class MyProgram
    { 
        static void Main (string[ ] args)
        { 
            Derived d = new Derived();
        } 
    } 
}