36. 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());
            }
        }
    

1. 1. 3

   
   
   

   2. 2

   
   
   

   3. 6

   
   
   

   4. 0

   
   
   

   5. Any Garbage Value

   
   
   

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1. 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().

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37. 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());
             }      
        }
    

1. 1. 0

   
   
   

   2. 1

   
   
   

   3. 2

   
   
   

   4. 3

   
   
   

   5. None of these

   
   
   

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1. 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.

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38. Map implements collection interface?

1. 1. False

   
   
   

   2. True

   
   
   

   3. Only A

   
   
   

   4. A and B both

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   Collection interface provides add, remove, search or iterate while map has clear, get, put, remove, etc.

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39. Which of the below does not implement Map interface?

1. 1. Hashtable

   
   
   

   2. HashMap

   
   
   

   3. Vector

   
   
   

   4. EnumMap

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   Vector implements AbstractList which internally implements Collection. Others come from implementing the Map interface.

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40. Which of these classes implements Set interface?

1. 1. DynamicList

   
   
   

   2. ArrayList

   
   
   

   3. HashSet

   
   
   

   4. LinkedList

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   HashSet and TreeSet implements Set interface where as LinkedList and ArrayList implements List interface.

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