8:00 Quiz 2

Statistics:

mean     22.824 (383.000/17)
stddev   4.176
median   23.000
midrange 21.000-26.000

#   avg
1   6.53 / 10
2   8.71 / 10
3   7.59 / 10

Question 2-1

Suppose a user executes the following run() method.

public static void run() {
    String str = "arboreteum";
    int j = 0;
    for(int i = 0; i < str.length(); i++) {
        if(str.charAt(i) == 'r') {
            IO.print(str.substring(j, i));
            j = i + 1;
        }
    }
    IO.println(str.substring(j));
}

Show all the values taken on by the variables of the program.

i
j

What does the method print?

Question 2-2

Say we've defined the following method.

public static int f(int n) {
    IO.println(n);
    return n / 2;
}

Also, say our program executes the line

IO.println(1 + f(1 + f(12)));

What is printed in executing this line?

Question 2-3

What does the following method print?

import csbsju.cs160.*;

public class Q3 {
    public static void run() {
        Account a = new Account();
        a.deposit(2.0);
        Account b = new Account();
        b.deposit(4.0);
        Account c = b;
        b = a;
        b.deposit(8.0);
        IO.println(a.getBalance());
        IO.println(b.getBalance());
        IO.println(c.getBalance());
    }
}

Solutions

Solution 2-1

i  0  1  2  3  4  5  6  7  8  9 10
j  0  2        5

It prints ``aboeteum''.

Solution 2-2

12
7
4

Solution 2-3

10.0
10.0
4.0