C# 1

Question 1

The [blank_start]switch[blank_end] statement selects for execution a statement list having an associated label
that corresponds to the value of an expression

Accepted Answer

switch

Question 2

Write the following code snippet:
 int n = 20;
 int d = n  5;
 What will be the value of d after this code snippet is executed?

Accepted Answer

25

Answer

26

Answer

27

Answer

28

Question 3

The [blank_start]do-while[blank_end] loop tests the condition at the bottom of the loop instead of at the top.

Accepted Answer

do-while

Question 4

Write the following code snippet:
 private static void WhileTest()
 {
 int i = 1;
 while (i < 5)
 {
 Console.WriteLine(“The value of i = {0}”, i);
 i;
 }
 }
 How many times will the while loop be executed in this code snippet?

Accepted Answer

4

Answer

0

Answer

1

Answer

5

Question 5

The only operator that takes three arguments is the [blank_start]?:[blank_end] operator

Accepted Answer

?:

Question 6

Write the following code snippet:
 int number1 = 10;
 int number2 = 20;
 if (number2 > number1)
 Console.WriteLine(“number1”);
 Console.WriteLine(“number2”);
 What output will be displayed after this code snippet is executed?

Accepted Answer

number1
number2

Answer

number1

Answer

number2

Answer

number2
number1

Question 7

The [blank_start]foreach[blank_end] loop is the most compact way to iterate through the items in a collection.

Accepted Answer

foreach

Question 8

In a switch statement, if none of the case statements match the switch expression, then
control is transferred to which statement?

Accepted Answer

default

Answer

break

Answer

continue

Answer

return

Question 9

On a 32-bit computer, a variable of int data type takes [blank_start]four[blank_end] bytes of memory

Accepted Answer

four

Question 10

You need to write code that closes a connection to a database, and you need to make
sure this code is always executed regardless of whether an exception is thrown. Where
should you write this code?

Accepted Answer

Within a finally block

Answer

Within a try block

Answer

Within a catch block

Answer

Within the Main method

Question 11

To access the first element of an array, you use an index of  [blank_start]0[blank_end]

Accepted Answer

0

Question 12

You need to store values ranging from 0 to 255. You also need to make sure that your
program minimizes memory use. Which data type should you use to store these values?

Accepted Answer

byte

Answer

char

Answer

short

Answer

int

Question 13

[blank_start]Recursion[blank_end] is a programming technique that causes a method to call itself in order to compute a result.

Accepted Answer

Recursion

Question 14

If you don’t have a base case in your recursive algorithm, you create an infinite recursion.
An infinite recursion will cause your program to throw an exception. Which exception
will your program throw in such a case?

Accepted Answer

StackOverflowException

Answer

OutOfMemoryException

Answer

DivideByZeroException

Answer

InvalidOperationException

Question 15

[blank_start]Constants[blank_end] are data fields or local variables whose value cannot be modified.

Accepted Answer

Constants

Question 16

You are learning how to develop repetitive algorithms in C#. You write the following
method:
 private static void ForTest()
 {
 for(int i = 1; i < 5;)
 {
 Console.WriteLine(“The value of i = {0}”, i);
 }
 }
 How many repetitions will the for loop in this code perform?

Accepted Answer

Infinite repetitions

Answer

0

Answer

4

Answer

5

Question 17

When an algorithm involves a large number of conditions, a(n) [blank_start]decision table[blank_end] is a compact
and readable format for presenting the algorithm.

Accepted Answer

decision table

Question 18

Which of the following C# features should you use to organize code and create globally
unique types?

Accepted Answer

Namespace

Answer

Assembly

Answer

Class

Answer

Data type

Question 19

A(n) [blank_start]flowchart[blank_end] is a graphical representation of an algorithm.

Accepted Answer

flowchart

Question 20

You write the following code snippet:
 int[] numbers = {1, 2, 3, 4};
 int val = numbers[1];
 You also create a variable of the RectangleHandler type like this:
 RectangleHandler handler;
 What is the value of the variable val after this code snippet is executed?

Accepted Answer

2

Answer

1

Answer

3

Answer

4

Question 21

You want to restrict the access for a method to the containing class or to a class that
is derived from the containing class. Which access modifier should you use for this
 method?

Accepted Answer

protected

Answer

public

Answer

private

Answer

internal

Question 22

A(n) [blank_start]class[blank_end] is a blueprint of an object.

Accepted Answer

class

Question 23

In a class, you defined a method called Render. This method provides functionality to
render bitmap files on the screen. You would like the derived classes to supersede this
functionality to support the rendering of additional image formats. You also want the
Render method of the derived classes to be executed even if a derived class is cast as the
base class. Which keyword should you use with the definition of the Render method in
the base class?

Accepted Answer

virtual

Answer

abstract

Answer

new

Answer

overrides

Question 24

A class that does not provide a complete implementation must be declared with the
keyword [blank_start]abstract[blank_end]

Accepted Answer

abstract

Question 25

You defined a class AdvMath that defines advanced mathematical functionality. You do
not want the functionality of this class to be inherited into derived classes. What
keyword should you use to define the AdvMath class?

Accepted Answer

sealed

Answer

abstract

Answer

private

Answer

internal

Question 26

Classes that want to support comparison must implement the IComparable interface and
then provide a body for the [blank_start]CompareTo[blank_end] method.

Accepted Answer

CompareTo

Question 27

You need to provide query functionality to several of your classes. Each class’s algorithm
for the query will likely be different. Also, not all the classes have an “is-a” relationship
with each other. How should you support this functionality?

Accepted Answer

Create a common interface that is implemented by all the classes

Answer

Add the query functionality to a base class with the public access modifier

Answer

Have all the classes inherit from an abstract base class and override the base-class
method to provide their own query functionality

Answer

Have all the classes inherit from a base class that provides the query functionality

Question 28

You can use the [blank_start]is[blank_end] operator to check whether it is legal to cast one type to
another type.

Accepted Answer

is

Question 29

Which of the following class elements should you use to define the behavior of a class?

Accepted Answer

Method

Answer

Property

Answer

Event

Answer

Delegate

Question 30

Three main features of an object-oriented programming language are [blank_start]encapsulation[blank_end],
[blank_start]inheritance[blank_end], and _ [blank_start]polymorphism[blank_end].

Accepted Answer

encapsulation

Accepted Answer

inheritance

Accepted Answer

polymorphism

Question 31

You are writing code for a class named Product. You need to make sure that the data members
of the class are initialized to their correct values as soon as you create an object of the
Product class. The initialization code should be always executed. What should you do?

Accepted Answer

Create a constructor in the Product class to initialize data members

Answer

Create a static method in the Product class to initialize data members

Answer

Create a static property in the Product class to initialize data members

Answer

Create an event in the Product class to initialize data members

Question 32

You can use [blank_start]namespaces[blank_end] to group related classes in order to reduce name collisions.

Accepted Answer

namespaces

Question 33

You are creating a new class named Square that is derived from the Polygon class. The
Polygon class has the following code:
class Polygon
{
 public virtual void Draw()
 {
 // additional code . . .
 }
}
 The Draw method in the Square class should provide new functionality but also hide the
Polygon class implementation of the Draw method. Which code segment should you use
to accomplish this?

Accepted Answer

class Square: Polygon
{
 public new void Draw()
 {
 // additional code . . .
 }
}

Answer

class Square: Polygon
{
 public override void Draw()
 {
 // additional code . . .
 }
}

Answer

class Square: Polygon
{
 public virtual void Draw()
 {
 // additional code . . .
 }
}

Answer

class Square: Polygon
{
 public static void Draw()
 {
 // additional code . . .
 }
}

Question 34

The [blank_start]this[blank_end] keyword refers to the current instance of a class.

Accepted Answer

this

Question 35

You are creating a new class named Rectangle. You write the following code:
class Rectangle: IComparable
{
 public double Length { get; set; }
 public double Width { get; set; }
 public double GetArea()
 {
 return Length * Width;
 }
 public int CompareTo(object obj)
 {
 // to be completed
 }
}
 You need to complete the definition of the CompareTo method to enable comparison of
the Rectangle objects. Which of the following codes should you write?

Accepted Answer

public int CompareTo(object obj)
{
 Rectangle target = (Rectangle)obj;
 double diff = this.GetArea() − target.GetArea();
 if (diff == 0)
 return 0;
 else if (diff > 0)
 return 1;
 else return −1;
}

Answer

public int CompareTo(object obj)
{
 Rectangle target = (Rectangle)obj;
 double diff = this.GetArea() − target.GetArea();
 if (diff == 0)
 return 1;
 else if (diff > 0)
 return −1;
 else return 0;
}

Answer

public int CompareTo(object obj)
{
 Rectangle target = (Rectangle)obj;
 if (this == target)
 return 0;
 else if (this > target)
 return 1;
 else return −1;
}

Answer

public int CompareTo(object obj)
{
 Rectangle target = (Rectangle)obj;
 if (this == target)
 return 1;
 else if (this > target)
 return −1;
 else return 0;
}

Question 36

A(n) [blank_start]delegate[blank_end] is a type that references a method

Accepted Answer

delegate

Question 37

You are writing code for a new method named Process:
void Process(object o)
{
}
 The code receives a parameter of type object. You need to cast this object into the type
Rectangle. At times, the value of o that is passed to the method might not be a valid
Rectangle value. You need to make sure that the code does not generate any System.
InvalidCastException errors while doing the conversions. Which of the following lines of
code should you use inside the Process method to accomplish this goal?

Accepted Answer

Rectangle r = o as Rectangle;

Answer

Rectangle r = (Rectangle) o;

Answer

Rectangle r = o is Rectangle;

Answer

Rectangle r = (o != null) ? o as rectangle: (Rectangle) o;

Question 38

A(n) [blank_start]struct[blank_end] is a value type, whereas a(n) [blank_start]class[blank_end] is a reference type.

Accepted Answer

struct

Accepted Answer

class

Question 39

You are writing code to handle events in your program. You define a delegate named
RectangleHandler like this:
public delegate void RectangleHandler(Rectangle rect);
You also create a variable of the RectangleHandler type as follows:
RectangleHandler handler;
 Later in the program, you need to add a method named DisplayArea to the method
invocation list of the handler variable. The signature of the DisplayArea method matches
the signature of the RectangleHandler method. Any code that you write should not
affect any existing event-handling code. Given this restriction, which of the following
codes should you write?

Accepted Answer

handler += DisplayArea;

Answer

handler = new RectangleHandler(DisplayArea);

Answer

handler = DisplayArea;

Answer

handler −= DisplayArea;

Question 40

You can use the [blank_start]static[blank_end] keyword to declare a member that belongs to the class
itself rather than to a specific object.

Accepted Answer

static

C# 1

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