C Sc 227 Practice Test 1 Answers for test 1, Friday 15-Feb-2008
1. Write a checkmark √ to the right of any assertion if it would pass. Leave the line in the comment blank
assertEquals(2, j / k); // a. ______
assertEquals(1, j % k); // b. ______
assertEquals(-0.5, x + 1, 1e-12); // c. ___√___
assertEquals('U', s.charAt(1)); // d. ______
assertEquals(5, s.indexOf("Arizona")); // e. __√____
assertEquals(0, s.indexOf("U of A")); // f. ___√___
assertTrue(s.compareTo("ASU") > 0); // g. ____√__
assertEquals(2.0, Math.sqrt(j), 1e-12); // h. ______
2. Complete the unit test for method grade (fill in the blanks) so it executes every branch of code in the
assertEquals( "A", grade(90.0) ); // or some argument > 90.
assertEquals( "B", grade(80.0) ); // or some argument > 80.0 and < 90.0
assertEquals( "C", grade(70.0) );
assertEquals( "D", grade(60.0) );
assertEquals( "E", grade(50.0) );
3. How many times will the following code print "Hello"? 0, Unknown, and Infinite are legitimate
int j = 1;
int n = 5;
while(j <= n) {
System.out.print("Hello");
n++;} Infinite
int j = 1;
while(j <= 11) {
System.out.print("Hello");
j = j + 3;
} 4
int n = 0;
for(int j = 1; j < n; j++) {
System.out.print("Hello");
} Zero
// Tricky Question
for(int j = 1; j <= 11; j++);
System.out.print("Hello"); 1
4. Write a for loop that prints this sequence of integers: -10 –5 0 5 10 15, … , 5555
for (int j = -10; j <= 5555; j = j + 5)
System.out.print (j + " ");
7. Complete method occurencesOf to return how often
public int occurencesOf(int search, Scanner scanner) {
int result = 0;
while(scanner.hasNext() ) {
int nextInt = scanner.nextInt();
if (nextInt == search)
result++;;
}
return result;
}
6. Write the output generated by the following code
5 5 6 2 3
8. Write an entire Java class named Histogram that allows for a visual peek at quiz scores where "*"
public class Histogram {
private double totalQuizScores;
private int numberOfTests;
public Histogram() {
totalQuizScores = 0;
1
