Computer Science Workshop Quiz

Which of the following is not a type of polymorphism in Java?

• Method overloading

• Operator overloading

• Operator overriding

• Method overriding

Which feature of OOPS described the reusability of code?

• Abstraction

• Encapsulation

• Polymorphism

• Inheritance

Which collection does not allow duplicate elements?

• List

• Set

• Map

• All of the above

Which collection allows you to retrieve elements in the order they were inserted?

• HashSet

• TreeMap

• LinkedHashMap

• PriorityQueue

What is the Output of following Java Program? import java.util.*; class Demo { public static void main(String[] args) { ArrayList arr = new ArrayList(); arr.add(11); arr.add(2); arr.add(3); arr.add(5); arr.add(7); arr.remove(new Integer(7)); arr.remove(2); for (int i = 0; i < arr.size(); i++) System.out.print(arr.get(i) + " "); } }

Which of these is an correct way of defining generic method?

• name(T1, T2, …, Tn) { /* … */ }

• public name { /* … */ }

• class name[T1, T2, …, Tn] { /* … */ }

• name{T1, T2, …, Tn} { /* … */ }

Which of the following collections is sorted by its natural ordering?

• HashMap

• TreeMap

• LinkedHashMap

• Hashtable

What is the Output of following Java Program? import java.util.*; class Demo { public static void main(String[] args) { LinkedHashMap hm = new LinkedHashMap(); hm.put("John", 3); hm.put("Ron", 1); hm.put("George", 2); hm.put("Ray", 4); for (Map.Entry e : hm.entrySet()) System.out.println( e.getKey() + " "+ e.getValue()); } }

The Comparable interface contains a method called________________.

• compare

• toCompare

• compareTo

• compares

What following code does? public final class Algorithm { public static void fun(T[] a, int i, int j) { T temp = a[i]; a[i] = a[j]; a[j] = temp; } }

• Interchanging the positions in an array

• Interchanging the values in an array

• Interchanging the values and positions in an array

• None of the above.