EECS 183 Winter 2016 Exam 2

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1 EECS 183 Winter 2016 Exam 2 Closed Book Closed Electronic Devices 3 5 Notecard Closed Neighbor Turn Off Your Cell Phones We will confiscate all electronic devices that we see - including cell phones, calculators, smart watches, etc. Multiple Choice Questions (20 questions 6 points per question = 120 points) KEY 1 Instructions: Read Carefully! 1.) You may have one personally handwritten 3 5 notecard. 2.) Some questions are not simple. Therefore, read carefully. 3.) Assume all code and code fragments are syntactically valid, unless otherwise specified. 4.) Assume/use only the standard C ) In all the given code, if any character looks like a space, it is one. 6.) On the scantron, bubble in your name and UMID. 10 pts off for incorrect UMID. 7.) On the scantron, bubble in Key pts off for missing or incorrect key. 8.) Sign below and print your uniqname. 10 pts off if we cannot read your uniqname. I have neither given nor received aid on this examination, nor have I concealed any violations of the Honor Code. uniqname Signature 1 of 10

2 This page is intentionally left blank. You may use it as scratch paper if needed. 2 of 10

3 1.) Which of the following is true of test-driven development? A. Test cases are written instead of functional code. B. Test cases and working code are written by a pair of programmers, one writing tests while the other works on the functionality. C. Test cases are written before writing the code for some new functionality. D. Code is first written then tested thoroughly in very small units. E. None of the above. 2.) Which of the following is a valid declaration of a 2D integer array named foo? A. int foo[5]; B. int foo[]; C. int foo[5][]; D. int foo[5][5]; E. int foo[][]; 3.) Considering the following code snippet, what prints? for (int i = 4; i < 6; i++) { for (int j = 4; j < 6; j++) { cout << "X" << " "; A. X X X X X X B. X X X X C. X X D. Nothing prints. E. None of the above. 4.) What are file streams used for? A. Printing information to the console. B. Selecting where to save your.cpp file. C. Reading from and writing to files. D. Reading information from the console. E. A and D. 3 of 10

4 Refer to the following class declaration for the next two(2) questions. class Person { public: Person(); Person(int currentage); void printage(); int age; ; 5.) Given the following main function, what is the correct way to increment by one the age data member of thisperson? int main() { Person thisperson; // increment age of thisperson here return 0; A. age++; B. Person.age++; C. thisperson.age++; D. thisperson::age++; E. You must implement a setter function to modify age. 6.) What is the correct way to access the member variable age in the implementation of the member function printage and print to the console using cout? A. cout << age; B. cout << Person; C. cout << Person.age; D. cout << Person(age); E. You must declare a getter function to access age. 7.) Given the following code snippet, which of the following prints a valid element of testarray? char testarray[3][3]; A. cout << testarray[3][3]; B. cout << testarray[2][1]; C. cout << testarray[][2]; D. Exactly two of the above are correct. E. None of the above. 4 of 10

5 8.) Given the following buggy function, which call(s) to dozensneeded would expose the bug? /** * Requires: units > 0 * Modifies: Nothing * Effects : Returns the number of dozens needed * to supply at least the number of items * specified by the parameter units */ int dozensneeded(int units) { return (units / 12); A. cout << dozensneeded(12); B. cout << dozensneeded(13); C. cout << dozensneeded(36); D. Both B and C. E. A, B, and C. 9.) When writing the definition for a member function for a class, the programmer has access to 1 member variables and functions. Outside the scope of a member function, the programmer has access to 2 member variables and functions. A. 1 - public and private 2 - private B. 1 - public and private 2 - public C. 1 - only private 2 - private D. 1 - only public 2 - private E. 1 - only private 2 - public 10.) Where and why must the scope resolution operator :: be used when working with classes? A. In the.cpp file for the class, to access the member variables declared in the header file. B. In the.cpp file for the class, to define the member functions declared in the header file. C. In the header file for the class, to declare member functions. D. In both the.cpp and header files for the class, so that the compiler knows the member function declarations and definitions are connected. E. Outside of the scope of the class, to access private member variables and functions. 5 of 10

6 11.) Considering the getstring function implemented below, which statement about getstring is true? string getstring(istream &inputstream) { string s; inputstream >> s; return s; A. getstring can read strings from cin. B. getstring can read strings from files. C. getstring s behavior is the same as that of getline. D. Exactly two of the above are true. E. A, B, and C are true. 12.) Given the function declaration for reflection, and the following declarations in main: void reflection(int matrix[][10]); int main() { int testmatrix[10][10] = {0; int anothermatrix[5][10] = {0; int yetanothermatrix[5][5] = {0; // make a valid call to reflection here! return 0; Which of the following are valid calls to reflection? A. reflection(testmatrix); B. reflection(anothermatrix); C. reflection(yetanothermatrix); D. Exactly two of the above are valid. E. A, B, and C are valid. 6 of 10

7 Refer to the following class declaration for the next two(2) questions. class Rectangle { public: Rectangle(); Rectangle(int widthin, int heightin); void setwidth(int widthin); void setheight(int heightin); int getheight(); int getwidth(); private: int width; int height; ; 13.) Which of the following are valid declarations of an instance of the class Rectangle? I. Rectangle r; II. Rectangle r(3); III. Rectangle r(3, 4); IV. Rectangle r(int x, int y); A. I B. I and III C. II and IV D. I, II, and III E. I, II, III, and IV 14.) Consider box is a previously declared instance of the Rectangle class. If you wanted to make a test case for the setter for height in the main function, which of the following code snippets is the best test case? A. box.setheight(10); cout << box.getheight(); B. box.getheight(); box.setheight(10); C. if (box.setheight(10) == box.getheight()) { 1tabcout << "It works"; D. if (box.getheight(10) == box.setheight()) { 1tabcout << "It works"; E. setheight(10); cout << getheight(); 7 of 10

8 15.) When executing the code snippet below, the user inputs 5 3 X 4 <enter> where <enter> denotes the user pressing the enter key. int x = 0; int sum = 0; while (cin >> x) { sum += x; Which of the following code snippets gets rid of the remainder of the line of input that caused the fail state? A. string junk; getline(cin, junk); cin.clear(); B. string junk; cin.clear(); getline(cin, junk); C. cin >> x; D. cin.good(); E. There is no fail state with cin given the code and input. 16.) Consider the following code snippet: ofstream file("data.txt"); int count = 10; while (count > 0) { file << count << " "; count--; Which of the following statement(s) are true? I. ofstream file("data.txt"); can be replaced with: 1tab1tab1tab ofstream file; 1tab1tab1tab file.open("data.txt"); II. ofstream has a non-default constructor that takes a file name as a parameter and opens the file. III. If successfully opened, the file data.txt will contain: A. III B. I and III C. II and III D. I, II, and III E. None of the statements are true. 8 of 10

9 17.) Which of the following are motivations to implement classes? A. Classes keep data and functionality together. B. Classes separate interface and implementation. C. Classes avoid code duplication. D. All of the above. E. None of the above. 18.) Consider the following declaration for the class Applicant: class Applicant { public: Applicant(); double getgpa(); void setgpa(double gpain); private: double applicantgpa; ; We want to add a non-default constructor to the declaration for the class Applicant above. Which of the following are valid constructor implementations? A. void Applicant::Applicant(double gpain) { 1tabapplicantGPA = gpain; B. Applicant::Applicant(double gpain) { 1tabApplicant newapplicant; 1tabnewApplicant.setGPA(gpaIn); 1tabreturn newapplicant; C. Applicant::Applicant(double gpain) { 1tabsetGPA(gpaIn); D. Exactly two of the above are valid constructors. E. A, B, and C are valid constructors. 9 of 10

10 Refer to the following class declaration for the next two(2) questions. class Book { private: string title; string ISBN; public: // constructors Book(); Book(string titlein, string ISBNIn); // setters for member variables void settitle(string titlein); void setisbn(string ISBNIn); ; // outputs the Book in format // title ISBN void print(); 19.) Which of the following code snippets, in main, will create an instance of the Book class with title set to "Harry Potter" and ISBN set to " "? A. Book mybook("harry Potter", " "); B. Book mybook = {"Harry Potter", " "; C. Book mybook; mybook.title = "Harry Potter"; mybook.isbn = " "; D. Exactly two of the above. E. A, B, and C. 20.) After sucessfully declaring an instance of the Book class named newbook, you want to test your settitle function, so you write the following line of code. newbook.settitle("hp"); Which of the following lines of code in main would you use to print the contents of member variables to test the settitle function? A. cout << newbook.title; B. cout << newbook.gettitle(); C. cout << newbook.print(); D. newbook.print; E. newbook.print(); 10 of 10

Multiple Choice Questions (20 questions * 5 points per question = 100 points)

Multiple Choice Questions (20 questions * 5 points per question = 100 points) EECS 183 Winter 2014 Exam 1 Closed Book Closed Notes Closed Electronic Devices Closed Neighbor Turn off Your Cell Phones We will confiscate all electronic devices that we see including cell phones, calculators,