Chapter 8 - Multiple Choice

Question 1

1. What are the valid ways to declare an 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. What is the index of the first element of an array?

❑ –1

❑ 0

❑ 1

Answer 2

0

Question 3

3. An array a has 30 elements; what is the index of its last element?

❑ 29

❑ 30

❑ 31

Answer 3

29

Question 4

4. What is the default value of the elements in an array of ints after declaration and instantiation of the array?

❑ 0

❑ null

❑ undefined

Answer 4

0

Question 5

5. How do you access the element of array a located at index 6?

❑ a{6}

❑ a( 6 )

❑ a[6]

Answer 5

a [6]

Question 6

6. Which of the following assertions is true?

❑ An array cannot be sized dynamically.

❑ An array can be sized dynamically, but cannot be resized without instantiating it again.

❑ An array can be sized dynamically and can also be resized without instantiating it again.

Answer 6

An array can be sized dynamically, but cannot be resized without instantiating it again

Question 7

7. How do you retrieve the number of elements in an array a?

❑ a . length( )

❑ a . length

❑ a . size( )

❑ a . size

Answer 7

a.length

Question 8

8. All the elements of an array must be of the same data type.

❑ true

❑ false

Answer 8

true

Question 9

9. Array aggregate assignment is possible in Java.

❑ true

❑ false

Answer 9

false

Question 10

10. Aggregate comparison of arrays is possible in Java.

❑ true

❑ false

Answer 10

false

(Explanation:
• Aggregate comparison operation is not allowed in java to compare each individual elements one array with other.
• To compare elements from one array to another array must be done with comparison operators (, <=,>=, ==, ! =)
• For example, int a[]={1,2,3,4,5};
• int b[]={1,2,3,4,5};
• a==b is incorrect comparison to check if two array contains same elements.
• Therefore, aggregate comparison is possible in java is incorrect statement.)

Question 11

11. An array can be returned by a method.

❑ true

❑ false

Answer 11

true

Question 12

12. A Sequential Search on a sorted array can be written more efficiently than a Sequential Search on an unsorted array.

❑ true

❑ false

Answer 12

false

(Explanation:

• Searching is a process to find a given key value in an array.
• In a sequential search process, each element of the array is searched from starting element to last element.
• Whether array is sorted or unsorted, each element of the array is searched with key element to find a match if key is in the array or not.
• The time-complexity of the sequential search is O(n)
• Therefore, the statement sequential search on a sorted array is faster than on an unsorted array is incorrect.)