Exam 2 (Mar 11)

Answer the sample exam questions on your own so you know what you need to study.

Sample Questions

Take the exam below on your own, closed book, without a computer. Set a 50-minute timer so you can practice finishing in the time alloted. The actual exam will be similar in difficulty and length to this exam.

exam2_sample.pdf

• These specific questions should not be construed as a study guide. The questions do not necessarily provide information about what you should and/or shouldn’t study. Try to write and answer different variants of each question. You may discuss your questions and answers with other students enrolled in the course.

• The answers to sample exams will not be made available. Of course, you can easily check your answers to many questions by editing, compiling, and/or executing the code. This is to help you avoid focusing too much attention on the specifics of these questions.

Tip

Practice drawing memory diagrams for Question 2 (EarRing, LipRing, NavelRing, and NoseRing) of the sample exam.

Memory Diagrams

Activity 8 and the Memory Diagrams tutorial may be helpful for reviewing the basics. For more practice, draw a memory diagram for each of the exercises below.

Exercise 1: Variables

long money = 50;
boolean good = true;
double price = money;
char hash = '#';
String rating = "PG";

Exercise 2: Arrays

int[] data = null;
int[] counts = {10, 3, 7, -5};
double[] scores = new double[3];
String[] words = new String[2];
String[] take = {"CS 159", "CS 227"};

int[] easy = {1, 2, 3};
int[] copy = easy;

Exercise 3: Methods

public static void main(String[] args) {
    int[] nums = {159, 227};
    printArray(nums);
}

public static void printArray(int[] a) {
    System.out.print("{" + a[0]);
    for (int i = 1; i < a.length; i++) {
        System.out.print(", " + a[i]);
    }
    System.out.println("}");
}

Exercise 4: Objects

public class Card {

    private int rank;  // 1=Ace, ..., 11=Jack, 12=Queen, 13=King
    private int suit;  // 0=Clubs, 1=Diamonds, 2=Hearts, 3=Spades

    public Card(int rank, int suit) {
        this.rank = rank;
        this.suit = suit;
    }

    public static void main(String[] args) {
        Card c1 = new Card(8, 1);
        Card c2 = new Card(12, 2);
        Card c3 = c1;
        c1 = c2;
    }
}

Exercise 5: Static

public class BankAccount {

    private static final String PREFIX = "1234";
    private static int nextNumber = 1;

    private String number;
    private String owner;
    private double balance;

    public BankAccount(String owner) {
        this.number = PREFIX + String.format("%04d", nextNumber);
        this.owner = owner;
        nextNumber++;
    }

    public static void main(String[] args) {
        BankAccount ba1 = new BankAccount("Stacie");
        BankAccount ba2 = new BankAccount("Trevor");
    }
}

Video 1: Classes

This video by Dr. Weikle was posted before Exam 1 but is also a great review of HW5 topics.

Video 2: Exceptions

Note: This video is from two years ago. File I/O is not on this year’s Exam 2. Feel free to watch the first half, stopping at 4:45. Or watch the entire video if you would like to see next week’s topic.