AJP-E2

What is the correct way to create an ArrayList of Strings?

• ArrayList<String> list = new ArrayList[];

• ArrayList list = new List<String>();

• ArrayList list = new ArrayList<String>();

• ArrayList<String> list = new ArrayList<>();

What is the output of the following code?

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

list.add("Java");

list.add("Python");

System.out.println(list.remove(0));

• Java

• Python

• true

• Compilation error

Which one is the correct way to iterate over elements in an ArrayList?

• for (int i = 0; i < list.size(); i++)

• for (int i : list)

• for (Object obj : list)

• for (Iterator it = list.iterator(); it.hasNext();

Which collection class provides a way to store elements in key-value pairs?

• ArrayList

• Maps

• LinkedList

• All

class Main {

public static void main(String args[]) {

int x = 2;

int y = 0;

for ( ; y < 10; y++) {

if (y % x == 0)

continue;

else if (y == 8)

break;

else

System.out.print(y + " ");

}

}

}

• 1 3 5 7

• 1 3 5 7 9

• 8

• None

Which one of the following collection classes can be used to store unique objects?

• HashSet

• LinkedHashMap

• ArrayList

• ALL

Which of the following methods is used to add an element to the end of an ArrayList?

• addLast()

• addEnd()

• add()

• append()

Which collection class is synchronized and thread-safe?

• ArrayList

• HashSet

• Vectors

• LinkedList

Which collection class in Java provides a fixed-size collection that does not allow adding or removing elements?

• ArrayList

• LinkedList

• HashSet

• Arrays

Which method is used to retrieve the first element from a Queue without removing it?

• peek()

• getFirst()

• element()

• front()