Deck 7: Arrays and Lists

Question 1

Which one of the following declaration statements is not a value type?

A) decimal grossPay = 0.0m;
B) int playerScore = 0;
C) bool qualify = false;
D) Random rand = new Random();

Answer 1

D

Question 2

Which one of the following statements assigns the value 40 to the first element in an array of integers named values?

A) values[-1] = 40;
B) values[0] = 40;
C) values[null] = 40;
D) values[1] = 40;

Answer 2

B

Question 3

A(n) ____________ is a special value that links a variable to an object.

A) linker
B) reference
C) operator
D) delimiter

Answer 3

B

Question 4

A(n) ____________ is an object that can hold a group of values that must all be the same data type.

A) matrix
B) Collection
C) array
D) container

Question 5

The ____________ creates an object in memory and returns a reference to that object.

A) .NET Framework
B) new operator
C) = operator
D) % operator

Question 6

An array's____________ indicates the number of values that the array should be able to hold.

A) reference variable
B) size declarator
C) element
D) subscript

Question 7

A variable that is used to reference an object is commonly called a(n) ____________.

A) reference variable
B) object variable
C) class variable
D) Boolean variable

Question 8

When a(n) ____________ variable is declared, the compiler sets aside, or allocates, a chunk of memory big enough to hold the variable's data.

A) reference type
B) uninitialized
C) value type
D) dynamic type

Question 9

Of the following statements, which one correctly initializes an int array named quarters with the values 1, 2, 3, and 4?

A) const int SIZE = 4; int[] quarters = new int[SIZE] { 1, 2, 3, 4 };
B) int[] quarters = new int[] { 1, 2, 3, 4 };
C) int[] quarters = { 1, 2, 3, 4 };
D) All of these statements are correct.

Question 10

Look at the following code sample: const int SIZE = 10;
Int[] values = new int[SIZE];
For (int index = 0; index < SIZE; index++)
{
Values[index] = index + 1;
}
When the loop is finished stepping through the values array, what value will be stored in values[0]?

A) 10
B) 11
C) 0
D) 1

Question 11

When you create a numeric array in C#, what default value is assigned to its elements?

A) null
B) 0
C) 255
D) −1

Question 12

The storage locations in an array are known as ____________.

A) values
B) sectors
C) compartments
D) elements

Question 13

Which one of the following assignment statements associates an int array, that can hold 12 integers, with a reference variable named scores?

A) scores = new int[12];
B) int[12] = new scores;
C) int scores[12];
D) new int scores[12]

Question 14

When you create an array, you can optionally initialize it with a collection of values called a(n) ____________.

A) initialization list
B) default group
C) element assembly
D) starting run

Question 15

It is preferred practice to use a(n) ____________ as an array's size declarator.

A) variable
B) literal value
C) named constant
D) object

Question 16

Which one of the following statements correctly declares a reference variable named values that can be used to reference an array of int?

A) int values[];
B) values[int];
C) int[] values;
D) int [values];

Question 17

What special value are the elements of an array of reference type objects equal to by default?

A) 0
B) void
C) −1
D) null

Question 18

Each element in an array is identified by a unique number known as a(n) ____________.

A) subscript
B) identifier
C) delimiter
D) vector

Question 19

When working with an array, it is important that you do not use a(n)____________.

A) invalid subscript
B) null value
C) assignment statement
D) initialization list

Question 20

Which one of the following statements is not a valid array declaration?

A) double[] parsecs = new double[10];
B) decimal[] sales = new decimal[24.5m];
C) string[] cities = new decimal[50];
D) int[] quarters = new int[4];

Question 21

C# provides a special loop known as the ____________, that automatically iterates once for each element in the array.

A) do-while loop
B) foreach loop
C) for loop
D) while loop

Question 22

A(n) ____________ occurs when a loop iterates one time too many or one time too few.

A) off-by-one error
B) buffer overrun
C) system crash
D) logic error

Question 23

____________ is a process that runs automatically in the background from time to time, removing all unreferenced objects from memory.

A) System cleanup
B) Garbage collection
C) Nullification
D) Non-maskable Interrupt

Question 24

The ____________ algorithm is much more efficient than a sequential search when the data set is very large.

A) random search
B) quick sort
C) binary search
D) combinatorial search

Question 25

When you process a(n) ____________, you must process only elements containing valid items.

A) partially filled array
B) reference copy
C) sequential search
D) Boolean expression

Question 26

Because arrays are always passed ____________, a method that receives an array as an argument has access to the actual array.

A) by value
B) globally
C) in memory
D) by reference

Question 27

Various techniques known as ____________ have been developed to locate a specific item in a larger collection of data, such as an array.

A) search engine schematics
B) search algorithms
C) database logic
D) search protocols

Question 28

When only a reference to an object is copied rather than the object's contents, the copy is called a(n) ____________.

A) shallow copy
B) memory copy
C) value copy
D) reference copy

Question 29

When calling a method and passing an array variable as an argument, the variable contains a ____________ to the array.

A) variable
B) value
C) reference
D) parameter

Question 30

With what value should the accumulator variable be initialized to calculate the total of all values in a numeric array?

A) null
B) false
C) 0
D) −1

Question 31

To compare the contents of two arrays, you must compare each of the ____________ in the two arrays.

A) memory locations
B) reference variables
C) elements
D) size

Question 32

To declare a two-dimensional array, two ____________ are required: The first one is for the number of rows, and the second one is for the number of columns.

A) reference variables
B) Boolean variables
C) named constants
D) size declarators

Question 33

The foreach loop is designed to work with a temporary, read-only variable known as the ____________.

A) loop variable
B) counter variable
C) iteration variable
D) foreach variable

Question 34

____________ arrays, also known as 2D arrays, can hold two sets of data.

A) Double-data
B) Two-dimensional
C) Row-column
D) Duel-derivative

Question 35

To successfully ____________ the contents of two variables, we need a third variable that can serve as a temporary storage location.

A) copy
B) exchange
C) reference
D) remove

Question 36

The ____________ works like this: The smallest value in the array is located and moved to element 0. The next smallest value is located and moved to element 1. This process continues until all the elements have been placed in their proper order.

A) bubble sort
B) binary search
C) Boolean swap
D) selection sort

Question 37

Look at the following code sample: int[] numbers = { 1, 2, 3, 4, 5 };
Int highest = numbers[0];
For (int index = 1; index < numbers.Length; index++)
{
If (numbers[index] > highest)
{
Highest = numbers[index];
}
}
What value will the highest variable contain when the loop finishes?

A) 1
B) 3
C) 5
D) 15

Question 38

____________ arrays can only hold one set of data.

A) One-dimensional
B) Two-dimensional
C) Data bound
D) Classical

Question 39

In C#, all arrays have a(n) ____________ that equals the number of elements in the array.

A) Element property
B) getSize method
C) Length property
D) GetBounds method

Question 40

The ____________ uses a loop to step through the elements in an an array one by one, from the first to the last.

A) sequential search algorithm
B) optimized search algorithm
C) binary search algorithm
D) basic array traversal algorithm

Question 41

A List object has a(n) ____________ that holds the number of items stored in the List.

A) Count property
B) Total property
C) Length property
D) Size property

Question 42

If you want to take out all items from a List object, call the ____________ method.

A) Clear
B) Reset
C) ClearAll
D) ReDim

Question 43

You can use the ____________ to take out an item at a specific index in a List.

A) Delete method
B) RemoveAt method
C) DeleteAt method
D) EraseAt method

Question 44

You can call the ____________ method to insert an item at a specific index position in a List object.

A) Put
B) Add
C) Insert
D) Place

Question 45

Memory allocated for a reference type variable is the actual location that will hold any value assigned to the variable.

Question 46

Look at the following code sample: int[,] values = { { 1, 2, 3, 4 },
{ 5, 6, 7, 8 } };
What is the value stored in values[1, 2]?

A) 2
B) 3
C) 6
D) 7

Question 47

Reference variables can only reference objects.

Question 48

Which one of the following statements correctly creates a List object named friendsList that holds strings?

A) string friendsList = new List;
B) friendsList(string);
C) List friendsList = new List;
D) List friendsList = new List();

Question 49

A(n) ____________ is similar to an array, but it can expand at runtime.

A) List object
B) sequential object
C) Random object
D) jagged array

Question 50

If you know the value of the item you want to take out from a List object, but you do not know the item's index, you can use the ____________.

A) - (minus) operator
B) Erase method
C) Remove method
D) Delete method

Question 51

A(n) ____________ is similar to a two-dimensional array, but the rows can have a different number of columns.

A) offset array
B) skewed array
C) jagged array
D) differential array

Question 52

Data types in C# − and the underlying .NET Framework − fall into two categories: value types and reference types.

Question 53

List objects, like arrays, are always passed to methods ____________.

A) by value
B) in memory
C) by reference
D) globally

Question 54

Look at the following code sample: const int ROWS = 2;
Const int COLS = 2;
Int[,] grid = new int[ROWS, COLS];
What is the total number of elements in the grid array?

A) 2
B) 4
C) 8
D) 16

Question 55

You can store a variety of data types in an array.

Question 56

Creating a reference type object typically requires the following two steps, which can optionally be coded in a single program statement:
1. Declare a reference variable.
2. Create an object and associate it with the reference variable.

Question 57

Look at the following code sample: const int ROWS = 8;
Const int COLS = 2;
Int[,] table = new int[ROWS, COLS];
Which one of the following statements stores the value 25 in the element located at the first row and second column of the table array?

A) table[1, 2] = 25;
B) table[0, 1] = 25;
C) table[2, 1] = 25;
D) table[1, 0] = 25;

Question 58

Because variables hold only single values, they can be cumbersome in programs that process lists of data.

Question 59

Traditional two-dimensional arrays, where each row has the same number of columns, are sometime referred to as ____________.

A) square arrays
B) rectangular arrays
C) box arrays
D) 2D arrays

Question 60

To add items to an existing List object, use the ____________.

A) += operator
B) & operator
C) Insert property
D) Add method

Question 61

When working with an array, you cannot use a subscript that is less than 0 or greater than the array size minus 1.

Question 62

Because the foreach loop automatically knows the number of elements in an array, you do not have to use a counter variable to control its iterations, as you would with a regular for loop.

Question 63

You can create an array to hold any single type of value.

Question 64

The default value of a string array's elements is null.

Question 65

Arrays are reference type objects.

Question 66

The sequential search algorithm is the simplest of all array searching algorithms.

Question 67

You access the individual elements in an array using their subscripts.

Question 68

An array's size declarator must be a nonnegative integer value.

Question 69

Because subscript numbering starts at 0, the subscript of the last element in an array is 1 less than the total number of elements in the array.

Question 70

When you use either the ref or out keywords before an array parameter, the receiving method does not automatically make a local copy of the array.

Question 71

The first element in an array is assigned subscript 1, the second element is assigned subscript 2, and so on.

Question 72

When reading the contents of a file into an array, your loop should always iterate until the array is full.

Question 73

To write the contents of an array to a file, open the file and use a loop to step through each array element, writing it to the file. Then close the file.

Question 74

The ref keyword creates an object in memory and returns a reference to the object it creates.

Question 75

Because array subscripts start at 1 rather than 0, you are not as likely to perform an off-by-one error.

Question 76

Arrays are always passed by value when passed as method arguments.

Question 77

If you provide an initialization list when declaring an array, you can leave out the size declarator, but you cannot leave out the new operator and its subsequent expression.

Question 78

You cannot reassign an array reference variable to a different array.

Question 79

When processing the contents of an array, the foreach loop does not provide a variable that can be used as an array subscript.

Question 80

An array's Length property is read-only, so you cannot change its value by trying to assign a new value to Length.