Quiz 02 sample questions

The quiz will have three questions, and cover material through the end of the List topics.

In the first question, you will read some code and write a concise, high-level, English description of the code’s action. For example:

public static <E> List<E> mystery(List<E> l, int i) {
  List<E> r = new ArrayList<>();
  for (int j = i; j < l.size(); j++) {
    r.add(l.get(j));
  }
  return r;
}

In the second question, you’ll identify a logic error in a short snippet of code. That is, you will find a conceptual error, not an error that the compiler would catch. Here is an example:

/** 
  * Swaps the `i`th and `j`th elements of the List `l`. 
  * Assume 0 <= i <= j <= l.size().   
  */
public static <E> void swap(List<E> l, int i, int j) {
  l.set(i, l.get(j));
  l.set(j, l.get(i));
}

In the final question, you will write a short class or method according to a textual description. For example, a question might state:

Write a method static <E> List<E> concatenate(List<E> l1, List<E> l2). concatenate should return, as a new list, all the elements of l1 followed by all the elements of l2, in the order they appeared.

For example, with an input of l1 = [1, 2, 5], l2 = [2, 4, 1]', it should return the list[1, 2, 5, 2, 4, 1]`.

Assume List and ArrayList are correctly imported.

You can check your answers here.