1. Output of the following code is:

delegate int NumberChanger(int n);

namespace DelegateApp

{

class TestDelegate

{

static int num = 10;

public static int AddNum(int p)

{

num += p;

return num;

}

public static int MultNum(int q)

{

num *= q;

return num;

}

static void Main(string[] args)

{

//create delegate instances

NumberChanger nc;

NumberChanger nc1 = new NumberChanger(AddNum);

NumberChanger nc2 = new NumberChanger(MultNum);

nc = nc1;

nc = nc2;

//Invoke

num = nc(5);

Console.WriteLine("Value of Num: {0}", num);

Console.ReadKey();

}

}

}

Value of Num: 55

Value of Num: 50

Value of Num: 15

Value of Num: 75

2. What modifier should be used with a method if you have a class which can be used directly, but for which you want inheritors to be able to change certain behavior.

abstract

override

virtual

protected

3. When you create an abstract method, you provide __________.

curly braces

method statements

all of these

the keyword abstract

4. Abstract classes and interfaces are similar in that __________.

you can instantiate concrete objects from both

you cannot instantiate concrete objects from either one

all methods in both must be abstract

neither can contain nonabstract methods

5. When you create any derived class object, __________.

the base class and derived class constructors execute simultaneously

the derived class constructor must execute first, then the base class constructor executes

the base class constructor must execute first, then the derived class constructor executes

neither the base class constructor nor the derived class constructor executes

6. In a program that declares a derived class object, you __________ assign it to a variable of its base class type.

cannot

can

must

should not