2010
Last COMP
1210
Fall Name: ____________________________
Exam 1 09/22/2010 Page 1 of 8
First Name: ________________________________
Multiple Choice (40 items @ 2.5 point each) Select the letter in front of the most correct answer, and
mark your scantron accordingly.
1. When an object is created, space is reserved in memory for that objects _________.
a. constructor
b. instance data
c. methods
d. class header
e. local variables
2. In which of the following lines of code is a variable declared but not initialized?
a. int var1 = 3;
b. int var2;
c. var2 = 1 / 6;
d. var1 = var2;
e. Integer i = new Integer(var1);
3. Which of the following lines contains a narrowing conversion?
a. double value1 = Double.parseDouble(str);
b. int value = "Exam 1!".length();
c. double value3 = (int) 3.5;
d. int value4 = 4;
e. both b and c
4. Fill in the blank in the Javadoc comment below:
/**
* Adds interest to the account balance.
*
* @________ The interest.
*/
public void addInterest(double rate)
a. param
b. return
c. param rate
d. return rate
e. param args
5. Which of the following is executed first when you run your Java application?
a. The constructor of your class
b. The main method of your class
c. The toString method of your class
d. All static methods of a class
e. None of the above
COMP
1210
Fall 2010
Exam 1 09/22/2010 Page 2 of 8
6. A private method is referred to as a(n) ________ method, while a public method is referred to as
a(n) ________ method.
a. static, class
b. class, static
c. support, service
d. static, service
e. service, static
7. Which of the following best describes the variable num?
Integer num = new Integer(10);
a. a double type variable
b. a reference type variable
c. a primitive type variable
d. a static variable
e. a constant field
8. Which of the following (if any) is not a valid variable name?
a. old
b. new
c. total$
d. an_input
e. All of the above are valid variable names.
9. Which of the following represents the Java interpreter on your computer and is responsible for
running your Java program?
a. jGRASP.exe
b. java.exe
c. javac.exe
d. run.exe
e. Any IDE can act as a Java interpreter.
10. Suppose that your program produces an incorrect answer as a result of integer division. What type
of error is produced?
a. a style error
b. a compile-time error
c. a run-time error
d. a logical error
e. All of the above are valid answers.
11. Which of the following instance fields violates encapsulation?
a. public static final int XMAX = 10;
b. private static final int POINTS = 1052;
c. private boolean isIt = true;
d. private double weight;
e. None of the above violates encapsulation.
COMP
1210
Fall 2010
Exam 1 09/22/2010 Page 3 of 8
12. Which of the following lines of code invokes a method?
a. private double yCoord;
b. public static void main(String[] args)
c. System.out.println("Invalid input");
d. public class PaymentMethod
e. b and d only
13. What is printed to standard output after the following line of code is executed?
System.out.println("The answer is: " + 24 + 25);
a. The answer is: 49
b. The answer is: 50
c. The answer is: 2425
d. The answer is: +49
e. The answer is: +50
14. Given the Java API specification below, what is the parameter type of the matches method?
a.
b.
c.
d.
e.
boolean
matches
String
regex
void
15. A ________ class diagram shows the relationships between classes in a project.
a. JDK
b. IDE
c. UML
d. ASCII
e. None of the above.
16. A(n) ________ method changes the ________ of the object.
a. accessor, state
b. state, accessor
c. mutator, behaviors
d. static, state
e. mutator, state
17. On which of the following line is the toString() method of the client object invoked implicitly?
a. System.out.print(client);
b. Client client = new Client("Adrian Beltre");
c. String name = client.getName();
d. Double.parseDouble(client.getNumber());
e. None of the above invokes a toString method implicitly.
COMP
1210
Fall 2010
Exam 1 09/22/2010 Page 4 of 8
18. Consider the following method header:
public boolean spend(double amountSpent)
Complete the code below to call the spend method:
________ x = customer.spend(userInput);
a. public
b. double
c. void
d. int
e. None of the above.
19. Which of the following provides the object equivalent of a primitive type?
a. Wrapper class
b. System class
c. The Scanner class
d. Math class
e. There is no object equivalent of a primitive type
20. What is the value of y after the following code is executed?
double y = 7 - 3 / 3 2;
a. -2.0
b. -1.0
c. 0.0
d. 2.0
e. 4.0
21. What is the value of guests after the following code is executed?
int guests = 0;
guests++;
a. -1
b. 0
c. 1
d. 2
e. 3
22. Which of the following consecutively executed lines of code performs conversion via promotion?
a. int number = 6;
b. double value = 2.3, actual = number;
c. System.out.println((double)number / value);
d. actual = number / value;
e. = value value / 2.0;
COMP
1210
Fall 2010
Exam 1 09/22/2010 Page 5 of 8
23. Which of the following lines of code modifies the String object referenced by the variable
strInput?
a. int total = strInput.length();
b. return strInput.replace("a", "@");
c. System.out.println("Input: " + strInput + "\n");
d. double x = Double.parseDouble(strInput);
e. None of the above.
24. The statement below provides a program access to the _________ class in the _________
package.
import java.io.PrintWriter;
a. io, java
b. java.io, PrintWriter
c. Writer, java.io.Print
d. java.io.Print, Writer
e. PrintWriter, java.io
25. In which of the following lines is a static method invoked?
a. int letters = strInput.length();
b. double x = Double.parseDouble("2.3");
c. cc.setHeight(6);
d. public static final int ACE = 1;
e. All of the above invoke static methods.
26. Which of the following lines would print the String referenced by the variable eventName in
double quotes?
a. System.out.println("\"eventName\"");
b. System.out.println(eventName);
c. System.out.println("eventName");
d. System.out.println("\""+eventName+"\"");
e. System.out.println("+eventName+");
27. Which of the following lines of code contains a reference variable?
a. public static final int PLAYER1 = 0;
b. Scanner scan = new Scanner(System.in);
c. private int score;
d. public void setVolume(double volumeIn)
e. converted = (double)num;
COMP
1210
Fall 2010
Exam 1 09/22/2010 Page 6 of 8
28. Which of the following lines directly invokes a constructor?
a. String output = new String("Red Sox");
b. public static void main(String[] args)
c. module.construct();
d. public class PaymentMethod
e. None of the above
29. Which of the following is a valid constructor header for the Product class?
a. public int Product(String name, double price)
b. public void Product(String name, double price)
c. public Construct(String name)
d. public Product()
e. Both a and b are valid
30. Below four variables are declared, of which, three are initialized in the declaration. Which of the
variables cannot be set to a new value in a subsequent assignment statement?
a. private double length;
b. public static final double CEILING = 65;
c. String bestTeam = "Patriots";
d. private boolean isIt = true;
e. All of the above variables length, CEILING, bestTeam, and isIt can be reassigned values.
31. Which of the following is a character literal?
a. private byte num;
b. 'y'
c. The Character class
d. import java.io.*;
e. char a;
32. What is the value of x after the following code is executed?
int x = 14 % 6;
a. 0
b. 2.333333
c. 20
d. 1
e. 2
COMP
1210
Fall 2010
Exam 1 09/22/2010 Page 7 of 8
Use the following code segment to answer questions 33 through 40. Questions 33 through 36 are fillin-the-blank with the choices to the right of the blank in caption boxes.
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public class CreditCard
{
private String customer;
private double balance, interest;
public CreditCard(String name, double rate){
customer = name;
33. a. boolean
interest = rate;
b. static
c. void
}
d. double
e. None of the above
public double spend(________ amountSpent){
balance += amountSpent;
34. a. return
return balance;
b. balance =
}
c. private
d. output =
public void chargeInterest(){
e. None of the above
________ balance + (balance * interest);
}
35. a. return
b. static
public ________ getBalance(){
c. void
return balance;
d. boolean
}
e. None of the above
public void payBalance(double amountPaid){
balance = balance - amountPaid;
36. a. return
}
b. static
c. output =
public String toString(){
d. String output =
e. None of the above
_______ "Name: " + customer + "\n"
+ "Interest rate: " + interest + "%\n"
+ "Balance: $" + balance + "\n";
return output;
}
}
37. Which of the following variables can be accessed by all methods in the CreditCard class?
a. amountPaid
b. customer
c. spend
d. output
e. rate
COMP
1210
Fall 2010
Exam 1 09/22/2010 Page 8 of 8
38. Which of the following is a formal parameter?
a. customer
b. String
c. double
d. output
e. None of the above
39. Which of the following lines of code correctly instantiates a CreditCard object?
a. CreditCard cc = CreditCard.instantiate();
b. CreditCard cc = new CreditCard(myName, ccRate);
c. CreditCard = new CreditCard(String myName, double ccRate);
d. CreditCard cc = new CreditCard(34, "Jane");
e. CreditCard cc = new CreditCard(String myName, double rate);
40. Which of the following lines of code correctly invokes the payBalance method?
a. CreditCard.payBalance();
b. CreditCard.payBalance(double amt);
c. CreditCard.payBalance(amt);
d. cc.payBalance(amt);
e. cc.payBalance(double amt)