University of Maryland College Park Department of Computer Science CMSC131 Spring 2019 Exam 1 FIRSTNAME LASTNAME PRINT IN UPPERCASE STUDENT ID e g 123456789 Instructions Please print your answers and use a pencil Do not remove the staple from the exam Removing it will interfere with the Gradescope scanning process To make sure Gradescope can recognize your exam print your name write your directory id at the bottom of pages with the text DirectoryId provide answers in the rectangular areas provided and do not remove any exam pages Even if you use the provided extra pages for scratch work they must be returned with the rest of the exam This exam is a closed book closed notes exam with a duration of 50 minutes and 200 total points Your code must be efficient Multiple choice questions have only one answer unless indicated otherwise You don t need to use meaningful variable names however we expect good indentation Grader Use Only 1 2 3 Total Problem 1 Miscellaneous Problem 2 Diagram Problem 3 Cashier Total 50 50 100 200 1 Problem 1 Miscellaneous 1 3 pts Java compilers produce a Assembly code b Byte Code c Machine code can run on the computer CPU d None of the above 2 3 pts The Java Virtual Machine runs Java code a b Java bytecode c HTML d None of the above 3 3 pts A class is a A blueprint for the structure of an object b An object c A Java Virtual Machine d None of the above 4 3 pts The following code fragment prints int y 4 int x y System out println x 5 3 pts The following code fragment prints int x 1 y 7 boolean answer x 0 y 8 System out println answer y 6 3 pts The expression Albert compareTo Bob returns a b c d false 0 true 7 false 8 true 8 a A negative number b A positive number c Zero d None of the above 7 3 pts When is the body of a do while never executed a When the appropriate condition is provided b Never a 4 b 5 c 0 d 45 8 3 pts Which of the following could be used to name variables in Java We are not asking if they are good style just whether or not they are permissible Circle all that apply Dream 34Warm flat car component 9 4 pts Name two primitive types used to store integers in addition to int and long 2 10 4 pts Assuming x y and z are integer variables complete the following assignment that will initialize the answer variable with the value true if x y and z are in increasing order and false otherwise For example 5 10 21 are in increasing order 5 3 21 are not boolean answer x y 11 10 pts Re write in the box the following code fragment using a for loop The body of the for loop can only have the System out println statement no other statement int y 3 val 10 while y 1 System out println val val val 2 y 12 4 pts Complete the following assignment so we are able to print the following message Notice that double quotes surround the message String path System out println path C home tmp 13 4 pts Define a String constant named BEST SCHOOL that has as value UMCP DirectoryId 3 Problem 2 Diagram Complete the program below that prints a rectangle The program will read the size an integer value It will then generate a rectangle with a number of rows that corresponds to size and a number of columns that is three times the number of rows One third of the rectangle columns leftmost ones use the character the rest will use the character Use the message Enter size to read data You can assume users will provide correct data and a size value larger than or equal to 1 Below we have provided two examples of running the program Underlined text represent input provided by the user Remember your program must work for other values You will lose credit if you use more than two loops in your solution a nested loop represents two loops Enter size 2 Enter size 5 public class Diagram public static void main String args Scanner scanner new Scanner System in 4 Problem 3 Cashier Complete the implementation of the program below that represents a cashier system in a supermarket This supermarket only sells two items bread with a cost of 2 00 and milk with a cost of 3 00 Your program will read an item s name using the message Enter item If the item entered is bread or milk you will increase the count of items seen by 1 and adjust the total amount due by the item s price An item can be entered multiple times each instance must be counted If the user enters done as an item s name the program will print the total number of items seen using the message Items and the total amount due using the message Total The number after Total does not need to have two decimal digits after the period any format is fine If the user enters as item s name something other than bread milk or done the program will print the message Invalid item and continue reading the next item Invalid items do not change the current item s count nor total amount due Below we are providing an example of running the program Underlined text represents input provided by the user Remember your program must work for other values Enter item milk Enter item paper Invalid item Enter item bread Enter item milk Enter item done Items 3 Total 8 0 public class Cashier public static void main String args Scanner scanner new Scanner System in DirectoryId 5 EXTRA PAGE IN CASE YOU NEED IT LAST PAGE 6
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