Which of the following is NOT a primitive data type in Java?  Which of the following lines declares a constant holding the value 42 in Java?

INSTRUCTIONS TO CANDIDATES

ANSWER ALL QUESTIONS

SECTION A

 Answers for this section must be written on the multiple-choice answer sheet (machine-readable form).

 Question 1 [2%]

 Which of the following is NOT a primitive data type in Java?

 

• char 

• double 

• int 

• number

  

Question 2 [2%]

 What output will be produced by the following Java program?

boolean a = true; boolean b = false; a = a && b;

b = ! b;

System.out.println(a + " " + b); 

 

• false false

• false true

• true false

• true true

 

Question 3 [2%]

 What output will be produced by the following Java program?

int a = 1; int b = 1;

while (a * b < 10) { a += b;

if (a == 4)

continue;

b++;

}

System.out.println(a + b);

 

• 7

• 8

• 9

• 10

 Question 4 [2%]

 Which of the following lines declares a constant holding the value 42 in Java?

 

• static final int ANSWER = 42;

• static const int ANSWER = 42;

• static final ANSWER = 42;

• static const ANSWER = 42;

Question 5

 A programmer has written a method which takes as its argument an array of integers and returns a new array with the same elements but in reverse order. Unfortunately one of the lines in the program has gone missing:

 

public static int[] revIntArray(int[] array) { int[] result = new int[array.length]; int index = array.length - 1;

for (int a : array) { result[index] = a;

// MISSING A LINE HERE

 

}

return result;

}

 

Which of the following lines should be inserted so that the method works correctly?

 

[A]     index++;

• index-= 1;

• a++;

[D]    a -= 1;

 Question 6 [2%]

 What output will be produced by the following Java program?

int[][] alpha = { {1, 2, 3 }, { 4, 5, 6 }};

int[] beta = alpha[0]; beta[1] = alpha[1][2];

System.out.println(alpha[0][1] + alpha[1][0]);

 

• 6

• 8

• 10

• 12

 

Question 7 [2%]

 Consider the following Java program

public class MainTest {

public static void main(String[] args) { if (args.length > 0)

System.out.println(main(args[0]));

}

public static String main() { return "Hello ";

}

public static String main(String x) { return main() + x;

}

}

 

Which of the following statements is true?

 

• The program will not compile because you cannot have methods with the same name in one

• When the program is run without a command line argument, it will throw a

StackOverflow exception.

• When the program is run without a command line argument, it will exit without displaying a message or throwing an

• When the program is run with the command line argument Jim, the console will display the message Hello Jim!

 Question 8 [2%]

 

Which of the following is NOT a java.util.Scanner method?

• getNext

• hasNext

• next

• nextDouble

Question 9 [2%]

 In the context of Java graphics programming, which of the following statements is true?

 

• Class JComponent has a paintComponent method that can be overridden in subclasses.

• The bottom-left corner of a window has coordinates (0,0) 

• Class JFrame has a drawOval method for drawing an ellipse or circle.

• The constructor invocation new JFrame("Hello World") will create a window with a content pane that shows the text "Hello World"

Question 10 [2%]

Which of the following statements about Java classes is false?

• A class can have several

• Classes can override the ==

• Classes can override method toString 

• Within a constructor, this is a reference to the current object which is being

Question 11 [2%]

 

Which of the following statements about Java access levels is false?

 

• A private method can access a public field of another

• A private method can only be accessed in its own class.

• A method without explicit access level is visible from the same

• A private data field can be read but not modified from outside the

 

Question 12 [2%]

 

Which interface does a Java class C need to implement in order for the method invocation

Arrays.sort(xs) to work properly where xs is an array of C elements?

 

• Order 

• Comparator 

• Ordering 

• Comparable 

Question 13

 

Consider the following statements about interfaces in Java:

• All methods declared in an interface are automatically public

• A class may implement at most one

• Both statements are

• The first statement is true; the second is

• The first statement is false; the second is

• Both statements are

Question 14 [2%]

 

Assume that List and ArrayList have been imported from package java.util

Which of the following statements does NOT compile?

 

• List<Integer> a = new ArrayList<>(); 

• List b = new ArrayList<Integer>(); 

• ArrayList c = new ArrayList<Integer>(); 

• ArrayList<Integer> d = new List<Integer>(); 

 

Question 15 [2%] 

Which of the following statements about Java class Object is false?

 

• In the absence of any other explicit superclass, every class is implicitly a subclass of

Object 

• Class Object has an equals method that compares objects for identity.

• Class Object has a toString method that prints the name and value of all

• Class Object is the only class which has no parent class.

Attachments:

Related Questions

. Introgramming & Unix Fall 2018, CRN 44882, Oakland University Homework Assignment 6 - Using Arrays and Functions in C

DescriptionIn this final assignment, the students will demonstrate their ability to apply two ma

. The standard path finding involves finding the (shortest) path from an origin to a destination, typically on a map. This is an

Path finding involves finding a path from A to B. Typically we want the path to have certain properties,such as being the shortest or to avoid going t

. Develop a program to emulate a purchase transaction at a retail store. This program will have two classes, a LineItem class and a Transaction class. The LineItem class will represent an individual

Develop a program to emulate a purchase transaction at a retail store. Thisprogram will have two classes, a LineItem class and a Transaction class. Th

. SeaPort Project series For this set of projects for the course, we wish to simulate some of the aspects of a number of Sea Ports. Here are the classes and their instance variables we wish to define:

1 Project 1 Introduction - the SeaPort Project series For this set of projects for the course, we wish to simulate some of the aspects of a number of

. Project 2 Introduction - the SeaPort Project series For this set of projects for the course, we wish to simulate some of the aspects of a number of Sea Ports. Here are the classes and their instance variables we wish to define:

1 Project 2 Introduction - the SeaPort Project series For this set of projects for the course, we wish to simulate some of the aspects of a number of