Question 1

Suppose that you have the following declaration. int[] alpha = new int[50]; int[][] beta = new int[10][5]; In this declaration, the array alpha has more components than the array beta.

Accepted Answer

The array alpha has 50 components, while the array beta has 10*5=50 components, so they have the same number of components.

Question 2

When a boolean array object is instantiated, its components are initialized to false.

Accepted Answer

In Java, when a boolean array is instantiated, all its elements are automatically initialized to false by default.

Question 3

Given the declaration int[] list = new int[50]; the statement System.out.println(list[0] + "..." + list[49]); outputs all 50 components of the array list.

Accepted Answer

The statement only outputs the first and the last elements of the array, not all 50 components.

Question 4

Given the declaration double[] numList = new double[20]; the statement numList[12] = numList[5] + numList[7]; updates the content of the thirteenth component of the array numList.

Accepted Answer

In Java, array indices start at 0, so numList[12] refers to the thirteenth element of the array.

Question 5

If a method has both a variable length formal parameter and other types of formal parameters, then the variable length formal parameter must be the first formal parameter of the formal parameter list.

Accepted Answer

A variable length formal parameter must be the last parameter in the parameter list, not the first.

Question 6

In row processing, a two-dimensional array is processed one row at a time.

Accepted Answer

Row processing involves handling each row of a two-dimensional array sequentially, processing all elements in one row before moving to the next.

Question 7

You can create an array of reference variables to manipulate objects.

Accepted Answer

An array of reference variables can be created to hold references to objects, allowing manipulation of those objects through the array.

Question 8

Only one-dimensional arrays can be passed as parameters.

Accepted Answer

In programming, multi-dimensional arrays can also be passed as parameters to functions or methods, not just one-dimensional arrays.

Question 9

In a method call statement, when passing an array as an actual parameter, you use only its name.

Accepted Answer

When passing an array to a method in Java, you only need to use the array's name, as it represents the reference to the array object.

Question 10

The statement int[] list = new int[15]; creates list to be an array of 14 components because array index starts at 0.

Accepted Answer

The statement creates an array with 15 components, indexed from 0 to 14.

Question 11

Suppose list is a one-dimensional array, wherein each component is of the type int. The following for loop correctly finds the sum of the elements of list. int sum = 0; for (int num : list) sum = sum + num;

Accepted Answer

The for-each loop iterates over each element in the list, adding each element's value to the sum, which correctly calculates the total sum of the elements.

Question 12

Arrays have a fixed number of elements.

Accepted Answer

Arrays have a fixed size, meaning that once an array is created, its size cannot be changed.

Question 13

The following statement creates alpha to be a two-dimensional array of 35 components. int[][] alpha = new int[20][15];

Accepted Answer

The statement creates a two-dimensional array with 20 rows and 15 columns, totaling 300 components, not 35.

Question 14

Java stores two-dimensional arrays in a row order form in computer memory.

Accepted Answer

Java stores two-dimensional arrays in a row-major order, meaning that the elements of each row are stored in contiguous memory locations.

Question 15

When an array object is instantiated, its components are initialized to their default values.

Accepted Answer

In most programming languages, when an array is instantiated, its elements are automatically initialized to default values based on the data type, such as 0 for integers, false for booleans, and null for objects.

Question 16

The array index can be any nonnegative integer less than the array size.

Accepted Answer

Array indices start at 0 and go up to one less than the size of the array, meaning they can be any nonnegative integer less than the array size.

Question 17

A single array can hold components of many different data types.

Accepted Answer

A single array typically holds elements of the same data type, although some programming languages offer structures like lists or tuples that can hold multiple data types.

Question 18

The base address of an array is the memory location of the first array component.

Accepted Answer

The base address of an array is defined as the memory location of the first element of the array, which is used to calculate the addresses of other elements in the array.

Question 19

In column processing, a two-dimensional array is processed one column at a time.

Accepted Answer

Column processing refers to operations performed on each column of a two-dimensional array independently, often used in data manipulation and analysis tasks.

Question 20

If an array index is less than or equal to zero, an InvalidIndexException exception is thrown.

Accepted Answer

In most programming languages, array indices start at zero, and negative indices are invalid. However, an exception like InvalidIndexException is not standard across all languages.

Quiz 9: Arrays