SE251:Session4ShortQuestions

Session 4 Short Answer Questions

1. Under what circumstances would a call to Iterator.next() throw a NoSuchElementException?

2. Is this valid:

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

3. Is this valid:

LinkedList<List> list = new LinkedList<List>();

4. What will be the output:

Vector<String> list = new Vector<String>();
list.add("hello");
Iterator<String> i = list.iterator();
System.out.println(i);

5. Is this valid:

Vector<String> list = new Vector<String>();
list.add("hello");
Iterator i = list.iterator();
String str = i.next();

6. What will be the output?

Vector<String> list = new Vector<String>();
list.add("one");
list.add("two");
Iterator<String> i = list.iterator();
System.out.println(i.next());

7. What will be the output?

TreeSet<String> list = new TreeSet<String>();
list.add("Pig");
list.add("Albatross");
list.add("Unicorn");
Iterator i = list.iterator();
System.out.println(i.next());

8. Which of the following lines are valid:

Queue queue = new LinkedList();
List list = new LinkedList();

9. HashMap does not implement Iterable, and neither do its superclasses. Nevertheless it is possible to obtain an iterator for the entries of a HashMap. How?