Exam 1. CSC 121 Spring Lecturer: Howard Rosenthal. March 1, 2017

Transcription

1 Exam 1. CSC 121 Spring 2017 Lecturer: Howard Rosenthal March 1, 2017 Your Name: Key 1. Fill in the following table for the 8 primitive data types. Spell the types exactly correctly. (16 points total) Data Type Number of Bytes byte 1 short 2 int 4 long 8 float 4 double 8 char 2 boolean 1 The following questions (or parts of questions) in numbers 2-16 are all worth 2 points each. 2. Answer the following as true or false a. _F_ System.out.println( ); and System.out.println( ); will print out the same String. b. _F_ Reserved words in Java are used as variables. c. _T_ The.class file created by the Java compiler is the input file to be executed by the Java Virtual Machine (JVM). d. _F_ (false (false && true)) always evaluates as true in Java. e. _F_ The switch expression in a switch statement can be of type double. f. _T_ Every else must have a corresponding if. g. _F_ The machine language of the JVM is Unicode. h. _T_ You may declare and initialize a variable in the same statement. i. _F_ int y = (int)(true); is a valid assignment statement. 1

2 3. The step by step procedure for solving a problem is called a(n) algorithm. 4. The lowest value for an 8-bit integer given two s complement representation is The smallest addressable unit of memory is called a byte. 6. Find the value of b int a =8; int b = a>7?(a-6):(a+6); 2 7. What is printed out based on this program segment? int var = 12/5; switch (var) { case 0: System.out.println( My value is + var); break; case 1: System.out.println( My value is + var); break; case 2: System.out.println( My value is + var); break; default: System.out.println( No match ); } My value is 2 2

3 8. What is the decimal value of: Convert 85 to 8-bit binary Show -39 as a eight bit binary in two s complement format flipped

4 11. Calculate the following assuming java rules apply with respect to typing 5+6/ /6 = Evaluate the following assuming Java rules apply ((5/6.0) >= (5/6)) true 13. Simplify this expression: X 87X (String) 14. Find the value of num at the end of the following segment: int newnum, num = 4; newnum = 1+ num++; num = 2*newNum++; What is the value of (true&&false) (3>=3) (false&&false) true 4

5 16. What does the segment below print to the screen? int first = 11, second = 3, third = 5; boolean b1 = true; if ((first%second > 3) (second%third < 2)) { System.out.print("It is a " +b1); } else { System.out.print("It is a " +(!b1)); } System.out.print(" statement."); It is a false statement 5

6 Extra Scratch Paper 6

7 Programs: 21 points each Pick any 2 of the 3. two.java files to csc121csudh@gmail.com Do not mail these files until you are done with the entire exam. No second mailing will be allowed 1. FreshPeaches Writes a program that does the following. Requests that the user inputs in the number of peaches that Jorge, Karla and Michael bought at the store. Determines the average number of peaches using Java integer arithmetic. Determines the percentage of the peaches bought by Jorge as a floating point number of type double The output will look like this: The average number of peaches is average. Jorge s percentage of the peaches is percent% Do no worry about rounding the percent. Note: items in italics are replaced by actual values. Please enter the number of peaches bought by Jorge, Karla and Michael respectively The average number of peaches is 1 Jorge's percent of the peaches is % Please enter the number of peaches bought by Jorge, Karla and Michael respectively The average number of peaches is 3 Jorge's percent of the peaches is 30.0% 7

8 2. Inches Write a program that prompts for the number of inches a quarterback threw for in his previous game. Convert that into yards, feet, and inches, and print the results. For instance, the output for 197 inches would be: Yards: 5 Feet: 1 Inches: 5 Please enter the number of inches the quarterback threw 197 Yards: 5 Feet: 1 Inches: 5 Please enter the number of inches the quarterback threw 22 Yards: 0 Feet: 1 Inches: 10 Please enter the number of inches the quarterback threw 96 Yards: 2 Feet: 2 Inches: 0 8

9 3. CartonCost Write a program that does the following: Requests from the user and reads in three prices for a carton of paper correct to two decimal places. Note: Assume that there is at least a one dollar difference in each of the three prices so that precision is not an issue. Calculate the total cost of 5 cartons of the least expensive, three cartons of the middle price and one carton of the most expensive. Prints out a statement that looks like this: The total cost of the cartons is $costofcartons. Note: items in italics are replaced by actual values. Please enter three different bids for the cartons, correct to two decimal places, with at least one dollar between each bid The total cost of the cartons is $14.0 Please enter three different bids for the cartons, correct to two decimal places, with at least one dollar between each bid The total cost of the cartons is $14.0 Please enter three different bids for the cartons, correct to two decimal places, with at least one dollar between each bid The total cost of the cartons is $14.0 Please enter three different bids for the cartons, correct to two decimal places, with at least one dollar between each bid The total cost of the cartons is $

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11 Extra Scratch 11