WorksheetsJava Arrays
Total questions: 10
Worksheet time: 9mins
Which of the following is FALSE about arrays on 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
Predict the output?
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
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
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
Which of the following is the correct way of importing an entire package ‘pkg’?
import pkg.
Import pkg.
import pkg.*
Import pkg.*
Which of the following is/are advantages of packages?
Packages avoid name clashes
Classes, even though they are visible outside their package, can have fields visible to packages only
We can have hidden classes that are used by the packages, but not visible outside.
All of the above
Which of these is a mechanism for naming and visibility control of a class and its content?
Object
Packages
Interfaces
None of the above
Which of this access specifies can be used for a class so that its members can be accessed by a different class in the same package?
Public
Protected
No Modifier
All of the mentioned
Arrays in Java are dynamically allocated using the . . . . operator.
create
dynamic
arrayList
new
Which of the following statements correctly declares a two-dimensional integer array?
int Matrix[ ] = new int[5,4];
int Matrix[ ]; Matrix = new int[5,4];
int Matrix[ ][ ] = new int[5][4];
int Matrix[ ][ ] = int[5][4];
