Chapter 9 - Multiple Choice

Question 1

1. What is/are the valid way(s) to declare a two-dimensional integer array named a? (Check all that apply.)

❑ int [ ][ ] a;

❑ int a [ ][ ];

❑ array [ ] int a;

❑ int array [ ] a;

Answer 1

int[ ][ ] a; and int a[ ][ ];

Question 2

2. A two-dimensional array is an array of arrays.

❑ true

❑ false

Answer 2

true

Question 3

3. In a two-dimensional array, every row must have the same number of columns.

❑ true

❑ false

Answer 3

false

Question 4

4. What is the default value of the elements of a two-dimensional array of booleans after declaration and instantiation of the array?

❑ true

❑ false

❑ undefined

Answer 4

false

Question 5

5. How do you access the element of array a located at row 2 and column 4?

❑ a{2}{4}

❑ a( 2,4 )

❑ a[2][4]

❑ a[4][2]

Answer 5

a[2][4]

Question 6

6. How do you retrieve the number of rows in a two-dimensional array a?

❑ a.rows

❑ a.length

❑ a.rows( )

❑ a.size

Answer 6

a.length

Question 7

7. How do you retrieve the number of columns in row 2 in a two-dimensional array a?

❑ a.length

❑ a[2].length

❑ a.size

❑ a[2].size

Answer 7

a[2].length

Question 8

8. All the elements of a two-dimensional array must be of the same type.

❑ true

❑ false

Answer 8

true

Question 9

9. An ArrayList can be returned by a method.

❑ true

❑ false

Answer 9

true

Question 10

10. It is possible to declare and instantiate an ArrayList of a user-defined class type.

❑ true

❑ false

Answer 10

true

Question 11

11. As we add objects to an ArrayList, how can we be sure it has enough capacity?

❑ Use the setCapacity method.

❑ Use the trimToSize method.

❑ We don’t need to do anything; capacity expands automatically as needed.

Answer 11

We don’t need to do anything; capacity expands automatically as needed

Question 12

12. Where does the add method of the ArrayList class add an object?

❑ at the beginning of the list

❑ at the end of the list

Answer 12

at the end of the list

Question 13

13. To what package does the class ArrayList belong?

❑ java.io

❑ java.util

❑ java.array

❑ java.list

Answer 13

java.util