Array and Array Operations
Which of the following is the correct way to declare a multidimensional array in Java?
a) int[] arr;
b) int arr[[]];
c) int[][]arr;
d) int[[]] arr;
Answer: c
1. Which of these best describes an array?
a) A data structure that shows a hierarchical behavior
b) Container of objects of similar types
c) Arrays are immutable once initialised
d) Array is not a data structure
Answer: b
2. How do you initialize an array in C?
a) int arr[3] = (1,2,3);
b) int arr(3) = {1,2,3};
c) int arr[3] = {1,2,3};
d) int arr(3) = (1,2,3);
Answer: c
3. How do you instantiate an array in Java?
a) int arr[] = new int(3);
b) int arr[];
c) int arr[] = new int[3];
d) int arr() = new int(3);
Answer: c
4. Which of the following is the correct way to declare a multidimensional array in Java?
a) int[] arr;
b) int arr[[]];
c) int[][]arr;
d) int[[]] arr;
Answer: c
5. What is the output of the following Java code?
public class array
{
public static void main(String args[])
{
int []arr = {1,2,3,4,5};
System.out.println(arr[2]);
System.out.println(arr[4]);
}
}a) 3 and 5
b) 5 and 3
c) 2 and 4
d) 4 and 2
Answer: a
6. What is the output of the following Java code?
public class array
{
public static void main(String args[])
{
int []arr = {1,2,3,4,5};
System.out.println(arr[5]);
}
}a) 4
b) 5
c) ArrayIndexOutOfBoundsException
d) InavlidInputException
Answer: c
7. When does the ArrayIndexOutOfBoundsException occur?
a) Compile-time
b) Run-time
c) Not an error
d) Not an exception at all
Answer: b
8. Which of the following concepts make extensive use of arrays?
a) Binary trees
b) Scheduling of processes
c) Caching
d) Spatial locality
Answer: d
9. What are the advantages of arrays?
a) Objects of mixed data types can be stored
b) Elements in an array cannot be sorted
c) Index of first element of an array is 1
d) Easier to store elements of same data type
Answer: d
10. What are the disadvantages of arrays?
a) Data structure like queue or stack cannot be implemented
b) There are chances of wastage of memory space if elements inserted in an array are lesser than the allocated size
c) Index value of an array can be negative
d) Elements are sequentially accessed
Answer: b
11. Assuming int is of 4bytes, what is the size of int arr[15];?
a) 15
b) 19
c) 11
d) 60
Answer: d
12. In general, the index of the first element in an array is __________
a) 0
b) -1
c) 2
d) 1
Answer: a
13. Elements in an array are accessed _____________
a) randomly
b) sequentially
c) exponentially
d) logarithmically
Answer: a