Self-Review Questions

1. What is a Set? List? Map?

   A set is a data structure that contains at most one of any element.

   A list is a data structure that contains any number of any element.

   A map is a data structure that contains (key, value) pairs where a key is assigned to at most one value.

2. What is an iterator and why are iterators necessary?

   An iterator is a type of object that is used to traverse a data structure.

3. Why can't you make an object of type ArrayList<int>? What should you do instead?

   Because int is a primitive and not an Object. You should do ArrayList<Integer>.

4. Implement a method that prints a given ArrayList<String> using an Iterator interface

   public void print(ArrayList<String> list){
   	Iterator<String> it = list.iterator();
   	while(it.hasNext()){
   		System.out.println(it.next());
   	}
   }
   
   

5. Implement a method that prints a given ArrayList<String> using a for-each loop

   public void print(ArrayList<String> list){
   	for(String s : list)
   		System.out.println(s);
   }
   

6. What are the advantages of using generics?

   type-checking support, more flexible code, code reuse.

7. Are generics available at runtime?

   ArrayList<String> as a type does not exist