Java Arrays

Question 1

C

class Test {
   public static void main(String args[]) {
     int arr[2];  
     System.out.println(arr[0]);
     System.out.println(arr[1]);
   }
}

• 0
  0

• garbage value
  garbage value

• Compiler Error
• Exception

Question 2

Output of following Java program?

Java

import java.util.Arrays;
class Test
{
    public static void main (String[] args) 
    {
        int arr1[] = {1, 2, 3};
        int arr2[] = {1, 2, 3};
        if (Arrays.equals(arr1, arr2))
            System.out.println(\"Same\");
        else
            System.out.println(\"Not same\");
    }
}

• Same
• Not Same

Question 3

Consider the following C program which is supposed to compute the transpose of a given 4 x 4 matrix M. Note that, there is an X in the program which indicates some missing statements. Choose the correct option to replace X in the program.

C

#include<stdio.h>
#define ROW 4
#define COL 4
int M[ROW][COL] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
main()
{
    int i, j, t;
    for (i = 0; i < 4; ++i)
    {
        X
    }
    for (1 = 0; i < 4; ++i)
        for (j = 0; j < 4; ++j)
            printf (\"%d\", M[i][j]);
}

A)	for(j = 0; j < 4; ++j){ t = M[i][j]; M[i][j] = M[j][i]; M[j][i] = t; }
B)	for(j = 0; j < 4; ++j){ M[i][j] = t; t = M[j][i]; M[j][i] = M[i][j]; }
C)	for(j = i; j < 4; ++j){ t = M[i][j]; M[i][j] = M[j][i]; M[j][i] = t; }
D)	for(j = i; j < 4; ++j){ M[i][j] = t; t = M[j][i]; M[j][i] = M[i][j]; }

• A
• B
• C
• D

Question 4

Output of following Java program?

C

class Test
{
    public static void main (String[] args) 
    {
        int arr1[] = {1, 2, 3};
        int arr2[] = {1, 2, 3};
        if (arr1 == arr2) 
            System.out.println(\"Same\");
        else
            System.out.println(\"Not same\");
    }
}

• Same
• Not Same

Question 5

Java

class Test {
   public static void main(String args[]) {
     int arr[] = new int[2];  
     System.out.println(arr[0]);
     System.out.println(arr[1]);
   }
}

• 0
  0

• garbage value
  garbage value

• Compiler Error
• Exception

Question 6

Java

class Test
{
    public static void main (String[] args) 
    {
        int arr1[] = {1, 2, 3};
        int arr2[] = {1, 2, 3};
        if (arr1.equals(arr2))
            System.out.println(\"Same\");
        else
            System.out.println(\"Not same\");
    }
}

• Same
• Not same

Question 7

Predict the output?

Java

// file name: Main.java
public class Main {
    public static void main(String args[]) {
       int arr[] = {10, 20, 30, 40, 50};
       for(int i=0; i < arr.length; i++)
       {
             System.out.print(\" \" + arr[i]);              
       }
    }
}

• 10 20 30 40 50
• Compiler Error
• 10 20 30 40

Question 8

Which of the following is FALSE about arrays in Java?

• A java array is always an object

• Length of array can be changed after creation of array

• Arrays in Java are always allocated on heap

Question 9

C

public class Main {
    public static void main(String args[]) {
        int arr[][] = new int[4][];
        arr[0] = new int[1];
        arr[1] = new int[2];
        arr[2] = new int[3];
        arr[3] = new int[4];
 
        int i, j, k = 0;
        for (i = 0; i < 4; i++) {
            for (j = 0; j < i + 1; j++) {
                arr[i][j] = k;
                k++;
            }
        }
        for (i = 0; i < 4; i++) {
            for (j = 0; j < i + 1; j++) {
                System.out.print(\" \" + arr[i][j]);
                k++;
            }
            System.out.println();
        }
    }
} 

• Compiler Error
•  0
   1 2
   3 4 5
   6 7 8 9 

•  0
   0 0
   0 0 0
   0 0 0 0 

•  9
   7 8
   4 5 6
   0 1 2 3