Description
In this workshop, you are to initialize the data within an object of class type upon its creation. LEARNING OUTCOMES Upon successful completion of this workshop, you will have demonstrated the abilities to: • define a constructor that initializes an object’s data at creation time • define a default constructor that sets an object to a safe empty state • describe what you have learned in completing this workshop SUBMISSION POLICY The in-lab section is to be completed during your assigned lab section. It is to be completed and submitted by the end of the workshop period. If you attend the lab period and cannot complete the in-lab portion of the workshop during that period, ask your instructor for permission to complete the in-lab portion after the period. If you do not attend the workshop, you can submit the in-lab section along with your at-home section (with a penalty; see below). The at-home portion of the lab is due on the day that is two days before your next scheduled workshop (23:59:59). All your work (all the files you create or modify) must contain your name, Seneca email and student number. You are responsible to back up your work regularly. LATE SUBMISSION PENALTIES: • In-lab portion submitted late, with at-home portion: 0 for in-lab. Maximum of 7/10 for the entire workshop. • If any of in-lab, at-home or reflection portions is missing, the mark for the workshop will be 0/10. IN-LAB (30%): Design and code a Passenger module for an airline application. Define a class named Passenger in the sict namespace. The class defines the structure of a passenger’s information for an airline company. The class holds the following private information: The passenger’s name: an array of characters of size 32 (including ‘\0’); The destination: an array of characters of size 32 (including ‘\0’); Your Passenger type includes the following member functions (which you need to implement — make sure to reuse existing code wherever possible instead of duplicating existing code): default constructor (a no-argument constructor): this constructor sets the Passenger object to a safe empty state; constructor with 2 parameters: The first parameter receives the address of a null-terminated C-style string containing the name of the passenger and the second parameter receives the address of a null-terminated C-style string containing the name of their destination. This constructor copies the data at the received addresses to the object instance variables, only if that data is valid. Data is valid if the address refers to a non-empty string; that is, data is not valid if its address is the null address or the string at that address is empty. If the data is not valid, this constructor sets the object to a safe empty state. bool isEmpty() const: a query that reports if the Passenger object is in a safe empty state. void display() const: a query that displays the contents of the Passenger object in the following format (see also the output listing below). PASSENGER-NAME – DESTINATION If the object is in a safe empty state, this function outputs the following message No passenger! Using the w4_in_lab.cpp implementation file of the main module shown below, test your code and make sure that it works. The expected output from your program is listed below this source code. The output of your program should match exactly this expected output. IN-LAB MAIN MODULE #include #include “Passenger.h” #include “Passenger.h” // this is intentional using namespace std; using namespace sict; int main() { sict::Passenger travellers[] = { Passenger(nullptr, “Toronto”), Passenger(“”, “Toronto”), Passenger(“John Smith”, nullptr), Passenger(“John Smith”, “”), Passenger(“John Smith”, “Toronto”), // valid Passenger(nullptr, nullptr), Passenger() }; cout << “—————————————-” << endl; cout << “Testing the validation logic” << endl; cout << “(only passenger 5 should be valid)” << endl; cout << “—————————————-” << endl; for (int i = 0; i < 7; ++i) { cout << “Passenger ” << i + 1 << “: ” << (travellers[i].isEmpty() ? “not valid” : “valid”) << endl; } cout << “—————————————-” << endl << endl; Passenger vanessa(“Vanessa”, “Paris”), mike(“Mike”, “Tokyo”), alice(“Alice”, “Paris”); cout << “—————————————-” << endl; cout << “Testing the display function” << endl; cout << “—————————————-” << endl; vanessa.display(); mike.display(); alice.display(); travellers[0].display(); cout << “—————————————-” << endl << endl; return 0; } IN-LAB OUTPUT —————————————- Testing the validation logic (only passenger 5 should be valid) —————————————- Passenger 1: not valid Passenger 2: not valid Passenger 3: not valid Passenger 4: not valid Passenger 5: valid Passenger 6: not valid Passenger 7: not valid —————————————- —————————————- Testing the display function —————————————- Vanessa – Paris Mike – Tokyo Alice – Paris No passenger! —————————————- IN-LAB SUBMISSION To test and demonstrate execution of your program use the same data as the output example above. If not on matrix already, upload Passenger.h, Passenger.cpp and w4_in_lab.cpp to your matrix account. Compile and run your code and make sure everything works properly. Then, run the following script from your account: (use your professor’s Seneca userid to replace profname.proflastname) ~profname.proflastname/submit 244_w4_lab and follow the instructions. IMPORTANT: Please note that a successful submission does not guarantee full credit for this workshop. If your professor is not satisfied with your implementation, your professor may ask you to resubmit. Resubmissions will attract a penalty. AT-HOME (30%) In the “at home” part of this workshop, you enhance your Passenger class by adding date information. Copy your Passenger module from your in-lab solution. Add data members that store the following additional information to your Passenger class: year of departure: an integer month of departure: an integer day of departure: an integer To manage this data, declare in your Passenger class definition, the following new member functions and implement them in the .cpp file of your Passenger module: constructor with 5 parameters: this constructor receives the addresses of the null-terminated C-style strings containing the passenger’s name and destination along with the year, month and day of departure. Like the other constructors, this constructor validates the parameters before accepting them. This constructor stores the data in the object’s instance variables only if all of the data received is valid. If any data is invalid, this constructor sets the object to a safe empty state. – Each string is valid if its address is not null and it is not empty; – The valid years are 2017, 2018, 2019, 2020 (inclusive); – The valid months are between 1 and 12 (inclusive); – The valid days are between 1 and 31 (inclusive); const char* name() const: a query that returns the address of the name of the passenger; the address of an empty string if the Passenger object is in a safe empty state. bool canTravelWith(const Passenger&) const: a query that receives an unmodifiable reference to a Passenger object and checks if the passenger referenced can travel with the current Passenger (two passengers can travel together if they are flying to the same destination on the same date). Modify your implementations of the constructor and display() member functions to include the date of departure in the format shown below (see also the output listing below): default constructor (a no-argument constructor): this constructor sets the object to a safe empty state, including the date variables; constructor with 2 parameters: The first parameter receives the address of a null-terminated C-style string containing the name of the passenger and the second parameter receives the address of a null-terminated C-style string containing the name of the destination. This constructor copies this data from into the instance variables and sets the departure date to July 1st, 2017, only if the data is valid. Data is valid if the address refers to a non-empty string; that is, data is not valid if its address is the null address or the string at that address is empty. If the data is not valid, this constructor sets the object to a safe empty state. void display() const: a query that displays the contents of the Passenger object in the following format (see also the output listing below). Note that the month and day values are in two-digit format zero-filled if necessary PASSENGER-NAME – DESTINATION on YEAR/MM/DD NOTE: Use the Passenger::display(…) function to print the name of a passenger in the examples above. NOTE: Use the Passenger::canTravelWith(…) function to check if two passengers can go together on vacation. Using the w4_at_home.cpp implementation file of the main module shown below, test your code and make sure that it works correctly. Below the source code is the expected output from your program. The output of your program should match exactly the expected one. AT-HOME MAIN MODULE #include #include “Passenger.h” using namespace std; using namespace sict; int main() { Passenger travellers[] = { Passenger(nullptr, “Toronto”, 2018, 4, 20), Passenger(“”, “Toronto”, 2018, 4, 20), Passenger(“John Smith”, nullptr, 2018, 4, 20), Passenger(“John Smith”, “”, 2018, 4, 20), Passenger(“John Smith”, “Toronto”, 2018, 4, 20), // valid Passenger(“John Smith”, “Toronto”, 2028, 4, 20), Passenger(“John Smith”, “Toronto”, 2014, 4, 20), Passenger(“John Smith”, “Toronto”, 2020, 12, 31), // valid Passenger(“John Smith”, “Toronto”, 2018, 40, 20), Passenger(“John Smith”, “Toronto”, 2018, 0, 20), Passenger(“John Smith”, “Toronto”, 2017, 1, 1), // valid Passenger(“John Smith”, “Toronto”, 2018, 4, 0), Passenger(“John Smith”, “Toronto”, 2018, 4, 32), Passenger(nullptr, nullptr, 0, 0, 0), Passenger() }; cout << “—————————————-” << endl; cout << “Testing the validation logic” << endl; cout << “(only passengers 5, 8 and 11 should be valid)” << endl; cout << “—————————————-” << endl; for (unsigned int i = 0; i < 15; ++i) { cout << “Passenger ” << i + 1 << “: ” << (travellers[i].isEmpty() ? “not valid” : “valid”) << endl; } cout << “—————————————-” << endl << endl; Passenger david(“David”, “Toronto”, 2018, 4, 20); Passenger friends[] = { Passenger(“Vanessa”, “Toronto”, 2018, 4, 20), Passenger(“John”, “Toronto”, 2018, 4, 20), Passenger(“Alice”, “Toronto”, 2018, 4, 20), Passenger(“Bob”, “Paris”, 2018, 1, 20), Passenger(“Jennifer”, “Toronto”, 2018, 4, 20), Passenger(“Mike”, “Toronto”, 2018, 4, 20), Passenger(“Sarah”, “Toronto”, 2018, 4, 20) }; cout << “—————————————-” << endl; cout << “Testing Passenger::display(…)” << endl; cout << “—————————————-” << endl; for (int i = 0; i < 7; ++i) friends[i].display(); cout << “—————————————-” << endl << endl; cout << “—————————————-” << endl; cout << “Testing Passenger::canTravelWith(…)” << endl; cout << “—————————————-” << endl; for (int i = 0; i < 7; ++i) { if (david.canTravelWith(friends[i])) cout << david.name() << ” can travel with ” << friends[i].name() << endl; } cout << “—————————————-” << endl << endl; return 0; } AT-HOME OUTPUT —————————————- Testing the validation logic (only passengers 5, 8 and 11 should be valid) —————————————- Passenger 1: not valid Passenger 2: not valid Passenger 3: not valid Passenger 4: not valid Passenger 5: valid Passenger 6: not valid Passenger 7: not valid Passenger 8: valid Passenger 9: not valid Passenger 10: not valid Passenger 11: valid Passenger 12: not valid Passenger 13: not valid Passenger 14: not valid Passenger 15: not valid —————————————- —————————————- Testing Passenger::display(…) —————————————- Vanessa – Toronto on 2018/04/20 John – Toronto on 2018/04/20 Alice – Toronto on 2018/04/20 Bob – Paris on 2018/01/20 Jennifer – Toronto on 2018/04/20 Mike – Toronto on 2018/04/20 Sarah – Toronto on 2018/04/20 —————————————- —————————————- Testing Passenger::canTravelWith(…) —————————————- David can travel with Vanessa David can travel with John David can travel with Alice David can travel with Jennifer David can travel with Mike David can travel with Sarah —————————————- REFLECTION (40%) Create a file reflect.txt that contains the answers to the following questions: 1) What is a safe empty state? Could you define another state as the safe empty state? 2) Describe how you have minimized code duplication. 3) Explain why the canTravelWith(…) member function can access the private data of the object referenced in its parameter. 4) What statement do you need to add to ensure that the strncpy(…) function executes correctly? 5) Explain what you have learned in this workshop. QUIZ REFLECTION: Add a section to reflect.txt called Quiz X Reflection. Replace the X with the number of the last quiz that you received and list the numbers of all questions that you answered incorrectly. Then, for each incorrectly answered question write your mistake and the correct answer to that question. If you have missed the last quiz, then write all the questions and their answers. AT-HOME SUBMISSION To submit the at-home section, demonstrate execution of your program with the exact output as in the example above. Upload reflect.txt, Passenger.h, Passenger.cpp and w4_at_home.cpp to your matrix account. Compile and run your code and make sure everything works properly. To submit, run the following script from your account (and follow the instructions): ~profname.proflastname/submit 244_w4_home IMPORTANT: Please note that a successful submission does not guarantee full credit for this workshop. If the professor is not satisfied with your implementation, your professor may ask you to resubmit. Resubmissions will attract a penalty.
