Java Ch 7 - Arrays - Quiz & Trivia

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

True

False

574-5

Explanation

574-5

2. Arrays have a fixed number of elements.

True

False

553

Explanation

553

3. 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.

True

False

556

Explanation

556

4. Which of the following is the array subscripting operator in Java?

.

{ }

New

[ ]

555

Explanation

555

5. Which of the following declares an array of int named beta?

Int beta;

Int[] beta;

New int beta[];

Int beta = int[];

553

Explanation

553

6. Char[][] table = new char[10][5]; How many dimensions are in the array seen in the accompanying figure?

1

2

5

10

590-1

Explanation

590-1

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

True

False

553

Explanation

553

8. What is the index number of the last component in the array numList seen in the accompanying figure?

0

30

49

50

556

Explanation

556

9. What is the output of the following Java code? int[] list = {0, 5, 10, 15, 20}; for (int j = 0; j < 5; j++) System.out.print(list[j] + " "); System.out.println();

0 1 2 3 4

0 5 10 15 20

0, 5, 10, 15, 20

0 5 10 15

559

Explanation

559

10. Char[][] table = new char[10][5]; How many rows are in the array seen in the accompanying figure?

0

5

10

15

590-1

Explanation

590-1

11. What is stored in alpha after the following code executes? int[] alpha = new int[5]; for (int j = 0; j < 5; j++) { alpha[j] = 2 * j; if (j % 2 == 1) alpha[j - 1] = alpha[j] + j; }

Alpha = {0, 2, 4, 6, 8}

Alpha = {3, 2, 9, 6, 8}

Alpha = {0, 3, 4, 7, 8}

Alpha = {0, 2, 9, 6, 8}

559

Explanation

559

12. Int[] numList = new int[50]; for (int i = 0; i < 50; i++) numList[i] = 2 * i; num[10] = -20; num[30] = 8; How many components are in the array numList seen in the accompanying figure?

0

30

49

50

553-4

Explanation

553-4

13. Int[] list = {1, 3, 5, 7}; for (int i = 0; i < list.length; i++) if (list[i] > 5) System.out.println(i + " " + list[i]); Which indices are in bounds for the array list, given the declaration in the accompanying figure?

0, 1, 2, 3

1, 2, 3, 4

1, 3, 5, 7

0, 1, 3, 5

564

Explanation

564

14. Consider the following method definition. public static int strange(int[] list, int listSize, int item) { int count = 0; for (int j = 0; j < listSize; j++) if (list[j] == item) count++; return count; } Which of the following statements best describe the behavior of this method?

This method returns the number of values stored in list.

This method returns the sum of all the values of list.

This method returns the number of times item is stored in list.

This method can process an array of doubles.

568-9

Explanation

568-9

15. Suppose that sales is a two-dimensional array of 10 rows and 7 columns wherein each component is of the type int. Which of the following correctly finds the sum of the elements of the fifth row of sales?

Int sum = 0;for(int j = 0; j < 7; j++) sum = sum + sales[5][j];

Int sum = 0;for(int j = 0; j < 7; j++) sum = sum + sales[4][j];

Int sum = 0;for(int j = 0; j < 10; j++) sum = sum + sales[5][j];

Int sum = 0;for(int j = 0; j < 10; j++) sum = sum + sales[4][j];

598

Explanation

598

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

True

False

554

Explanation

554

17. What is the value of alpha[4] after the following code executes? int[] alpha = new int[5]; for (int j = 0; j < 5; j++) alpha[j] = 2 * j - 1;

One

Three

Five

Seven

559

Explanation

559

18. Char[][] table = new char[10][5]; What is the value of table.length?

0

5

10

15

592-3

Explanation

592-3

19. Suppose you have the following declaration. double[] salesData = new double[500]; Which of the following range is valid for the index of the array salesData. (i) 0 through 500 (ii) 0 through 499

Only (i)

Only (ii)

Both i and ii

556

Explanation

556

20. How many objects are present after the code fragment in the accompanying figure is executed?

1

2

7

14

565-6

Explanation

565-6

21. Given the following method heading public static void mystery(int list[], int size) and the declaration int[] alpha = new int[75]; Which of the following is a valid call to the method mystery?

Mystery(alpha[75], 50);

Mystery(alpha[], 50);

Mystery(alpha, 40);

Mystery(int[75], alpha)

570-1

Explanation

570-1