Quiz 5

Wednesday

With a piece of paper, write down your name and answers to the following questions.

  1. What is the value of data[3][4] in the following 2D array?

    int[][] data = new int[6][];
    data[0] = new int[] {1, 2, 3, 4, 5};
    data[1] = new int[] {6, 7, 8};
    data[2] = new int[] {9, 10, 11, 12};
    data[3] = new int[] {13, 14, 15, 16, 17, 18};
    data[4] = new int[] {19, 20, 21, 22};
    data[5] = new int[] {23, 24, 25, 26};

    1. 12
    2. 17
    3. 15
    4. Accessing data[3][4] generates an error.
  2. Which of the following is not true about static members?

    1. It is not necessary for an instance of a class to be created to execute static methods or use static fields
    2. Static members are created by placing the keyword static in the definition.
    3. A static method cannot access instance members of the class using the keyword this
    4. Multiple separated instances of a static field may exist
  3. What attribute does the compareTo method of an enum use to compare two enum constants? E.g.,

    public class Program {
      public static void main(final String[] args) {
        int result = Gender.Female.compareTo(Gender.Male);
        :
      }
    }
    enum Gender {
      Confidential,
      Male,
      Female;
    }

    Answer: Ordinal.

  4. Determine if the following statement is correct and why?

    A problem can be solved recursively if it can be broken down into successive smaller problems that are different from the overall problem.

    Answer: False, the successive smaller problems need to be the same as the overall problem

Student Performance and Statistics

A histogram of student performance on percentage grades for Quiz 5 on Wednesday.

100% 2 90 - 99% 7 80 - 89% 1 70 - 79% 2 60 - 69% 0 50 - 59% 0 40 - 49% 0 30 - 39% 0 20 - 29% 1 10 - 19% 0 0 - 9% 0

A table showing the average performance for each question in Quiz 5 on Wednesday.

Q1 1.0 / 1 Q2 0.9 / 1 Q3 0.6 / 1 Q4 1.6 / 2