Collections
- Which of this method is used to change an element in a LinkedList Object?
-
View Hint View Answer Discuss in Forum
NA
Correct Option: D
An element in a LinkedList object can be changed by first using get() to obtain the index or location of that object and the passing that location to method set() along with its new value.
- What is the output of this program?
import java.util.*;
public class Result
{
public static void main(String args[])
{
ArrayList object = new ArrayList();
object.add("Y");
object.add("O");
object.add("U");
System.out.println(object.size());
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: D
3
- What is the output of this program?
import java.util.*;
public class Result
{
public static void main(String args[])
{
ArrayList object = new ArrayList();
object.add("Y");
object.add("O");
object.add("U");
object.ensureCapacity(5);
System.out.println(object.size());
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: A
Although object.ensureCapacity(5); has manually increased the capacity of object to 5 but the value is stored only at index 3, therefore object.size() returns the total number of elements stored in the object i:e 3, it has nothing to do with ensureCapacity().
- What is the output of this program?
import java.util.*;
public class Output
{
public static void main(String args[])
{
ArrayList object = new ArrayList();
object.add("Y");
object.add("O");
object.add("U");
object.ensureCapacity(3);
object.trimToSize();
System.out.println(object.size());
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: D
trimTosize() is used to reduce the size of the array that underlines an ArrayList object.
- What is the output of this program?
import java.util.*;
public class Arraylist_Example
{
public static void main(String args[])
{
ArrayList object = new ArrayList();
object.add("L");
object.add("V");
object.add("E");
object.add(1, "O");
System.out.println(object);
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: C
object is an object of class ArrayList hence it is an dynamic array which can increase and decrease its size. object.add(“n”) adds to the array element n and object.add(1,”n”) adds element n at index position 1 in the list, Hence object.add(1,”O”) stores O at index position 1 of obj and shifts the previous value stored at that position by 1.
