Core Java Quiz - 2

What is an ArrayList in Java?

• A fixed-size array

• A resizable array

• A linked list

• A map data structure

How is memory allocated for elements in an ArrayList?

• Elements are stored in a continuous block of memory

• Elements are stored in separate memory locations

• Elements are stored in a binary tree structure

• Memory allocation depends on the ArrayList's size

How does the ArrayList differ from a regular array in Java?

• ArrayLists can hold primitive data types, while arrays cannot

• ArrayLists are dynamically resizable, while arrays have a fixed size

• ArrayLists are faster for element access compared to arrays

• ArrayLists cannot store objects, only arrays can

What's the initial capacity of an ArrayList, and what happens if you exceed this capacity?

• Initial capacity is 0, and exceeding it results in an exception

• Initial capacity is 10, and exceeding it causes the ArrayList to automatically resize

• Initial capacity is based on the size of the first element, and exceeding it causes a compile error

• Initial capacity is unlimited, and exceeding it causes a memory overflow

How do you add an element to an ArrayList?

• Using the addElement() method

• Using the add() method

• Using the insert() method

• Using the push() method

What will be the output of the below ArrayList program?

import java.util.ArrayList;

import java.util.List;

public class Test {

public static void main(String[] args) {

ArrayList<String> al = new ArrayList<String>();

al.add("A");

al.add("B");

al.add("A");

al.add(null);

System.out.println(al);

}

}

• Compile time error

• [A, B, null]

• [A, B]

• [A, B, A, null]

Find the output of the below ArrayList program?

import java.util.ArrayList;

import java.util.List;

public class Test {

public static void main(String[] args) {

List<String> al1 = new ArrayList<String>();

al1.add("A");

al1.add("B");

List<String> al2 = new ArrayList<String>();

al2.add("P");

al2.add("Q");

al1.addAll(al2);

System.out.println(al1);

}

}

• [A, B]

• [P, Q]

• [A, B, P, Q]

• [P, Q, A, B]

What happens if you try to add an element at an index that is out of the current range of elements in an ArrayList?

• The element is added to the end of the ArrayList

• An exception is thrown: IndexOutOfBoundsException

• The ArrayList is automatically resized to accommodate the new element

• The element is discarded and lost

How can you remove an element from an ArrayList?

• Using the removeElement() method

• Using the erase() method

• Using the delete() method

• Using the remove() method

What is the difference between ArrayList and LinkedList in Java?

• ArrayList is faster for element insertion, while LinkedList is faster for element access

• ArrayList is faster for element access, while LinkedList is faster for element insertion (Answer)

• ArrayList cannot store objects, only LinkedList can

• There is no significant difference between ArrayList and LinkedList