Lab 3 Solutions

Starting Out with Programming Logic and Design 12 Solutions Lab 3: Decisions and Boolean Logic Note to Instructor: This lab accompanies Chapter 4 of Starting Out with Programming Logic & Design, with a focus on if statements and relational operators. Material in the chapter should have been covered prior to lab assignment. Evaluation: The instructor should be present to answer any questions and observe the student performing the lab. The student should turn in a hard copy (paper) or soft copy (email) of their work. Learning Objectives for this lab include: Understand how relational operators function. Understand how Boolean expressions process. Learn how to write an if statement in pseudocode, flowcharts, and Python code. Lab 3.1 walks the student through the process of evaluating Boolean expressions. Labs 3.2, 3.3, and 3.4 use the following programming problem. A retail company assigns a $5000 store bonus if monthly sales are $100,000 or more. Additionally, if their sales exceed 125% or more of their monthly goal of $90,000, then all employees will receive a message stating that they will get a day off. Lab 3.5 uses the following programming problem. Write a program that will ask the user to enter a person’s age, their weight, and their birth month. Your program will compare the entered values to the following and print the appropriate responses. Be sure to use modules. The Secret Answers The Comparison The Printed Response age = 25 If the guessed age is less than or equal to 25 Congratulations, the age is 25 or less weight = 128 If the guessed weight is greater than or equal to 128 Congratulations, the weight is 128 or more birthMonth = ‘April’ If the guessed birth month is equal to April Congratulations, the birth month is April Lab 3.1 – Evaluating Conditions Step 1: Consider the following values set to variables. myAge = 32 yourAge = 18 myNumber = 81 yourNumber = 17 votingAge = 18 myName = “Katie” yourName = “Bob” Step 2: Based on the values to the variables in Step 1, do the following conditions result in a true or false statement? The condition True or False myAge >= yourAge True yourAge > myAge False myAge == 45 False yourAge == votingAge True votingAge >= yourAge True myAge <= votingAge False myName != yourName True myNumber <= myAge True yourNumber >= myAge False yourNumber != 17 False Step 3: Based on the values to the variables in Step 1, what is the expected output? Hint: The output will either be what is printed to the screen, or "nothing." The condition Expected Output If myName == yourName Then print “We have the same name” End If Nothing If myAge >= yourAge Then print “I am older or equal to your age” End If I am older or equal to your age If myName != “Katie” Then print “That is not my name” End If Nothing If myName == “Katie” Then print “That is my name” End If That is my name If myNumber == 17 Then print “My number is 17” End If Nothing If myNumber >=80 Then print “My number is 80 or more” End If My number is 80 or more If yourNumber <= yourAge Then print “Your number is less than or equal to your age” End If Your number is less than or equal to your age If myNumber < yourNumber Then print “My number is less” End If Nothing If yourAge >= votingAge Then print “You can vote” End If You can vote If myAge < yourAge Then print “I am younger” End If Nothing Lab 3.2 – Pseudocode and Decisions Step 1: This program is easiest when solved using just one variable. Declare the variables that you will need in the program, using the proper data type and documenting the purpose. Depending on your programming style, you may find that additional variables are useful. If that is the case, adjust your program as necessary. Variable Name Purpose Real monthlySales Stores the monthly sales Step 2: Given the major task involved in this program, what modules might you consider including? Also describe the purpose of the module. Module Name Purpose Module getSales () Allows the user to enter the monthly sales. Module isBonus () This module will determine if a bonus should be awarded. Module isDayoff () This module will determine if a day off should be awarded. **Note: Their module names may be different, but should indicate the main task. Step 3: Complete the pseudocode by writing the missing lines. When writing your modules and making calls, be sure to pass necessary variables as arguments and accept them as reference parameters if they need to be modified in the module. (Reference: Writing a Decision Structure in Pseudocode, page 118). Module main () //Declare local variables Declare Real monthlySales //Function calls Call getSales(monthlySales) Call isBonus(monthlySales) Call isDayoff(monthlySales) End Module //this module takes in the required user input Module getSales(Real Ref monthlySales) Display “Enter the total sales for the month.” Input monthlySales End Module //this module will determine if a bonus is awarded Module isBonus(Real monthlySales) If monthlySales >=100000 Then Print “You get a bonus of $5,000!!!” End If End Module //this module will determine if all employees get a day //off. If sales are greater than or equal to 112500, then //they get a day off. Module isDayoff(Real monthlySales) If monthlySales >= 112500 Then Print “All employees get a day off!!!” End If End Module Lab 3.3 – Flowcharts Note to Instructor: Steps 1 – 8 walk students through the process of using Raptor and designing a flowchart. Step 9 requires students to show their completed flowchart. Variable names and statements will vary from student to student. Also, the lab can be completed using a different flowcharting application such as Visio. If so, the sample solution below will look a little different, but should still have the same fundamental steps. Instructors should grade on clear variable names, proper flow of program, the correct calculation, and the right output. Below is a sample solution to the programming problem. Step 9: Main Module getSales Module isBonus Module isDayOff Module Lab 3.4 – Python Code Note to Instructor: Steps 1 – 8 in this lab require students to write Python code to create a program. Their final program is required in Step 9. Step 9: #Student Name #Date #Description: This program determines if a bonus should be awarded #The main function def main(): print 'Welcome to the program' monthlySales = getSales() # gets sales #Function call to determine bonus isBonus(monthlySales) #Function call to determine day off isDayoff(monthlySales) #This function gets the monthly sales def getSales(): monthlySales = input('Enter the monthly sales $') monthlySales = float(monthlySales) return monthlySales #This function determines if there is a bonus def isBonus(monthlySales): if monthlySales >= 100000: print "You have earned a $5,000 bonus!!!" #This function determines if employees get a day off def isDayoff(monthlySales): if monthlySales >= 112500: print "All employees get a day off!!!" #calls main main() Lab 3.5 – Programming Challenge 1 – Guess the Secrets The Pseudocode Module main () //Declare local variables Declare Integer age Declare Integer weight Declare String birthMonth //Function calls Call getAge(age) Call getWeight(weight) Call getMonth(birthMonth) Call correctAnswers(age, weight, birthMonth) End Module //this module takes in the age Module getAge (Integer Ref age) Display “Enter your guess for age: ” Input age End Module //this module takes in the weight Module getWeight (Integer Ref weight) Display “Enter your guess for weight: ” Input weight End Module //this module takes in the birth month Module getAge (String Ref birthMonth) Display “Enter your guess for birth month: ” Input birthMonth End Module //this module will determine if guesses are correct Module correctAnswers(Integer age, Integer weight, String birthMonth) If age <= 25 Then Print “Congratulations, the age is 25 or less.” End If If weight >= 128 Then Print “Congratulations, the weight is 128 or more.” End If If birthMonth == ‘April’ Then Print “Congratulations, the birth month is April.” End If End Module The Flowchart Main Module getAge Module getWeight Module getMonth Module correctAnswers Module The Python Code #Secret Answers #the main function def main(): print #prints a blank line age = getAge() weight = getWeight() birthMonth = getMonth() print correctAnswers(age, weight, birthMonth) #this function will input the age def getAge(): age = input('Enter your guess for age: ') return age #this function will input the weight def getWeight(): weight = input('Enter your guess for weight: ') return weight #this function will input the age def getMonth(): birthMonth = raw_input('Enter your guess for birth month: ') return birthMonth #this function will determine if the values entered are correct def correctAnswers(age, weight, birthMonth): if age <= 25: print 'Congratulations, the age is 25 or less.' if weight >= 128: print 'Congratulations, the weight is 128 or more.' if birthMonth == 'April': print 'Congratulations, the birth month is April.' #calls main main()