In order for an instance of a derived class to completely take over a class member from a base class, the base class has to declare that member as

1. It is a keyed collection.
2. It is a ordered collection.
3. It is an indexed collection.
4. It implements a IDictionaryEnumerator interface in its inner class.
5. The key - value pairs present in a HashTable can be accessed using the Keys and Values properties of the inner class that implements the IDictionaryEnumerator interface.

    int[] a = {11, 3, 5, 9, 4}; 

1. The array elements are created on the stack.
2. Refernce a is created on the stack.
3. The array elements are created on the heap.
4. On declaring the array a new array class is created which is derived from System.Array Class.
5. Whether the array elements are stored in the stack or heap depends upon the size of the array.

1. Arrays can be rectangular or jagged.
2. Rectangular arrays have similar rows stored in adjacent memory locations.
3. Jagged arrays do not have an access to the methods of System.Array Class.
4. Rectangular arrays do not have an access to the methods of System.Array Class.
5. Jagged arrays have dissimilar rows stored in non-adjacent memory locations.

1. A switch statement can act on numerical as well as Boolean types.
2. A switch statement can act on characters, strings and enumerations types.
3. We cannot declare variables within a case statement if it is not enclosed by { }.
4. The foreach statement is used to iterate through the collection to get the desired information and should be used to change the contents of the collection to avoid unpredictable side effects.
5. All of the expressions of the for statement are not optional.

1. int[ , ] a;
   a = new int[2, 3]{{7, 1, 3},{2, 9, 6}};

2. int[ , ] a;
   a = new int[2, 3]{};

3. int[ , ] a = {{7, 1, 3}, {2, 9,6 }};

4. int[ , ] a;
   a = new int[1, 2];

5. int[ , ] a;
   a = new int[1, 2]{{7, 1, 3}, {2, 9, 6}};

String str = "She sells sea shells on the sea-shore"; 
int i;
i = str.SecondIndexOf("s");

String str = "She sells sea shells on the sea-shore"; 
int i, j;
i = str.FirstIndexOf("s"); 
j = str.IndexOf("s", i + 1);

String str = "She sells sea shells on the sea-shore"; 
int i, j;
i = str.IndexOf("s"); 
j = str.IndexOf("s", i + 1);

String str = "She sells sea shells on the sea-shore"; 
int i, j;
i = str.LastIndexOf("s"); 
j = str.IndexOf("s", i - 1);

String str = "She sells sea shells on the sea-shore"; 
int i, j;
i = str.IndexOf("S"); 
j = str.IndexOf("s", i);

namespace CuriousTabConsoleApplication
{
    class Baseclass
    { 
        int i;
        public Baseclass(int ii)
        {
            i = ii;
            Console.Write("Base "); 
        } 
    } 
    class Derived : Baseclass
    {
        public Derived(int ii) : base(ii)
        {
            Console.Write("Derived ");
        } 
    } 
    class MyProgram
    { 
        static void Main(string[ ] args)
        { 
            Derived d = new Derived(10);
        } 
    } 
}

public sample operator + ( sample a, sample b )

public abstract operator + ( sample a, sample b)

public abstract sample operator + (sample a, sample b )

public static sample operator + ( sample a, sample b )