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ECE Advanced Program, CSE 142 QUIZZ

April 18, 2011

SOLUTIONS

Quizz instructions

Quizz duration is 40 minutes.

Quizz is closed-book, closed-notes, closed-neighbors. No electronic devices may be used, including

calculators.

Exercise 1: Syntax errors

The following program contains 10 errors! What are they (just underline the errors and write the correct

code on the same line as the error)?

public class Tricky {

public static voidmain(String[]args) {

System.out.println("Hello world");

System.out.println("Do you like this program?");

System.out.println();

System.out.println("I wrote it myself.");

}

}

Exercise 2: Expressions

Write the results of each of the following expressions.

12 / 5 + 8 / 4 4

3 * 4 + 15 / 2 19

-(1 + 2 * 3 + (1 + 2) * 3) -16

42 % 5 + 16 % 3 3

SE 142 - QUIZZ file:///home/marc/danang/cse142/exam/quizz/quizz-solu...

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Exercise 3: More Expressions

Write the results of each of the following expressions.

5 * 6 / 4 % 3 - 23 / (14 % 6) -10

30 % 9 + 5 % 8 - 11 % 4 % 2 7

1 + 9 / 2 * 2.0 9.0

2.5 * 2 + 17 / 4 9.0

4.5 / 3 / 2 + 1 1.75

46 / 3 / 2.0 / 3 * 4/5 2.0

50 / 9 / 2.0 + 200 / 10 / (5.0 / 2) 10.5

Exercise 4: Values

What are the values of a, b, and cafter the following statements? Write your answers in the boxes on the

right.

int a = 5;

int b = 10;int c = b;

a++; // a? 6

b--; // b? 9

c = c + a; // c? 16

Exercise 5: More values

What are the values of i, j, and kafter the following statements? Write your answers on the right.

int i = 2;

int j = 3;

int k = 4;int x = i + j + k;

i = x - i - j; // i? 4

j = x - j - k; // j? 2

k = x - i - k; // k? 1

Describe in a few lines what is the code really doing:


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Exercise 6: What's the output?

Write the output produced by the fo llowing Java program:

public class OddStuff {

public static void main(String[] args) {

int number = 32;

for (int count = 1; count


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Exercise 8: More forloop

Complete the following code:

public class Triangle {

private static int max = 4;


for (int line = 1; line


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Exercise 10: Parameter Mystery

Fill in the boxes with the output that each method call would produce:

public class MysterySoda {


String soda = "coke"; String pop = "pepsi";

String coke = "pop";

String pepsi = "soda";

String say = pop;

carbonated(coke, soda, pop); // say coke not pepsi or pop

carbonated(pop, pepsi, pepsi); // say soda not soda or pepsi

carbonated("pop", pop, "koolaid"); // say pepsi not koolaid or pop

carbonated(say, "say", pop); // say say not pepsi or pepsi

}

public static void carbonated(String coke, String soda, String pop) {

System.out.println("say " + soda + " not " + pop + " or " + coke);

}

}

Exercise 11: More parameter Mystery

Fill in the boxes with the output that each method call would produce:

public class MysteryNumbers {

public static void main(String[] args) { String one = "two";

String two = "three";

String three = "1";

int number = 20;

sentence(one, two, 3); // three times two = 6

sentence(two, three, 14); // 1 times three = 28

sentence(three, three, number + 1); // 1 times 1 = 42

sentence(three, two, 1); // three times 1 = 2

sentence("eight", three, number / 2); // 1 times eight = 20

}

public static void sentence(String three, String one, int number) {

System.out.println(one + " times " + three + " = " + (number * 2));

}

}


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Exercise 12: if/elsemystery

Consider the following Java code. Fill in the boxes with the output produced by each of the method calls.

public static void mystery(int n) {

System.out.print(n + " ");

if (n > 10) {

n = n / 2; } else {

n = n + 7;

}

if (n * 2 < 25) {

n = n + 10;

}

System.out.println(n);

}

mystery(40); 40 20

mystery(8); 8 15

mystery(0); 0 17

mystery(12); 12 16

mystery(20); 20 20

Exercise 13: More if/elsemystery

Consider the following Java code. Fill in the boxes with the output produced by each of the method calls.

public static void mystery2(int a, int b) {

if (a < b) {

a = a * 2;

}

if (a > b) {

a = a - 10;

} else {

b++;

}

System.out.println(a + " " + b);

}

mystery2(10, 3); 0 3

mystery2(6, 6); 6 7

mystery2(3, 4); -4 4


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mystery2(4, 20); 8 21


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Exercise 14: Even More if/elsemystery

Consider the following Java code.

public static void mystery3(int x, int y) {

int z = 4;

if (z


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Exercise 18: Even more whileloop mystery

Fill in the boxes below with the output produced by each method call.

public static void mystery3(int x) {

int y = 0;

while (x % 2 == 0) {

y++; x = x / 2;

}

System.out.println(x + " " + y);

}

mystery3(19); 19 0

mystery3(42); 21 1

mystery3(48); 3 4

mystery3(40); 5 3

mystery3(64); 1 6


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