Computer Science II Project 4 Solution

Objectives: The main objectives of this project is to test your ability to create and use C++ classes, with multiple constructors, static members/functions, and expand to operator overloading. A review of pointers, structs, arrays, iostream, file I/O and C-style strings is also included.

Description:

This project will significantly expand upon Project 3 by adding additional functionality, and implementing more abstract data types (ADTs) and their operations through classes. Pointers must be used for all array manipulation, including arrays with ADTs (structs, classes) e.g, rental cars, rental agencies. Pointers must be used in function prototypes and function parameter lists - not square brackets. Make sure all your C-string functions (e.g. string copy, string compare, etc.) work with pointers (parameters list and function implementation). Const should be used in parameter lists, functions, and function signatures as appropriate. Square brackets should be used only when declaring an array, or if otherwise you specify your own overloaded operator[] . Pointer arithmetic (e.g., ++ , +=, - -, -=) and setting the pointer back to the base address using the array name can be used to move through arrays.

The additional functionality is as follows: You are given an updated data file where there is 1 Agency location (Agency) which has 5 cars (Car) which can potentially be of a high-tech type. Each car can incorporate up to 3 (0-3) special driving sensors (Sensor). You will have similar menu options, but the functionality has been updated below. Note: using multiple helper functions to do smaller tasks will make this project significantly easier.

The Sensor Class will contain the following private data members:
    • m_type, a C-string char array of 256 max characters (name of sensor type), valid strings for

Sensor m_type are "gps", "camera", "lidar", "radar", "none".

    • m_extracost, a float (additional rent cost per day for the car that carries the sensor, for "gps":=$5.0/day, for "camera":=$10.0/day, for "lidar":=$15.0/day, for "radar":=$20.0/day, for "none":=$0.0/day)

    • gps_cnt, a static int member (keeps track of existing gps-type sensors)

    • camera_cnt, a static int member (keeps track of existing camera-type sensors)

    • lidar_cnt, a static int member (keeps track of existing lidar-type sensors)

    • radar_cnt, a static int member (keeps track of existing radar-type sensors)

and will have the following methods:
    • Default Constructor – will set the aforementioned data members to default initial values.

    • Parameterized Constructor – will create a new object based on a C-string value passed into it (sensor type being instantiated). Hint: bear in mind what a sensor “type” implies about its other data members.

    • Copy Constructor – will create a new object which duplicates an input Sensor Object.

    • get/set methods for appropriate data member(s).

    • A get and a reset static member function to return and to reset each of the static member variables.

    • A Method to check if 2 Sensor Objects are the same. You must implement this as an operator overload of (operator==), and more specifically as a regular function (non-Member function of the Class).
The Car Class will contain the following private data members:
    • m_make, a C-string char array of 256 max characters (car make)

    • m_model, a C-string char array of 256 max characters (car model)

    • m_year, an int (year of production)

    • m_sensors, a Sensor class type array of size 3 (max allowable number of sensors per car). Hint: You are allowed to use an auxiliary member variable of your choice to keep track of how many actual sensors exist onboard, this will also help for instance in case adding a new sensor is required.

    • m_baseprice, a float (price per day for the sensorless vehicle)

    • m_finalprice, a float (price per day with the increased cost of the car sensors)

    • m_available, a  bool (1 = true; 0 = false; try to display true/false using the

"std::boolalpha" manipulator like: cout << boolalpha << boolVariable; )
    • m_owner, a C- string char array of 256 max characters (the current lessee; if no lessee, i.e.

the Car object is available), set to a ‘\0’-starting (0-length) C-string).

and will have the following methods:
    • Default Constructor – will set the aforementioned data members to default initial values.

    • Parameterized Constructor – will create a new object based on the values passed into it for the make, model, year, baseprice, and sensors.
    • Copy Constructor – will create a new object which duplicates an input Car object.

    • get methods for data members.

    • set methods for data members except the m_sensors, and m_finalprice.

    • updatePrice – a method to update the m_finalprice after any potential changes (to the m_baseprice or the m_sensors)
    • print – will print out all the car’s data.

    • estimateCost – will estimate the car’s cost given (a parameter passed to it) a number of days to rent it for.

    • A Method to Add a Sensor to the Car object. You must implement this as an operator overload of (operator+), and more specifically as Member function of the Class.

    • A Method to Add a lessee (the name of a lessee) to the Car object. You must implement this as another operator overload of (operator+), again as a Member function of the Class. Hint: bear in mind what side-effects on other data members the operation of “adding a renter” to a Car object might have.

The Agency Class will contain the following private data members:
    • m_name, a C-string char array of 256 max characters.

    • m_zipcode, an int variable (Note: not an array as in the previous Project any more).

Extra Grade Opportunity: Try to make this a const int for +5 extra points. In such a case, the readAllData method will obviously not be capable of modifying the m_zipcode value.

    • m_inventory, an array of Car objects with a size of 5.

and will have the following methods:
    • Default Constructor – will set the aforementioned data members to default initial values.

    • get/set (IF possible) methods for m_name and m_zipcode data members – by-Value.

    • A Method to Index by-Reference an Object of the m_inventory data (i.e. you should use return by-Reference). Hint: This will allow you to access (read and write) to the agency’s inventory like in Project_3.) You must implement this an operator overload of (operator[]). Reminder: Any calls to this operator are excluded from the Project’s restrictions about using brackets.

    • readAllData – read all of the data for the agency from a user-provided file.

    • printAllData - prints out all of the data for an agency (including car info).

    • printAvailableCars – prints out all of the data (including Car info) only for the available Car Objects of the agency.

The menu must have the following updated functionality:

    • 1) Read ALL data from file. The provided sample file HighTechAgency.txt is structured : The first line is the car agency info, followed by 5 cars.

For each car the order is: year make model baseprice {sensors} available [lessee]. The sensors are enclosed in {braces} and can be 0 up to 3 ws-separated names. The lessee name is [optional], it will only be there if the car is available.

    • 2) Print to terminal ALL data for the Agency and all its corresponding Cars in a way that demonstrates this relationship (similarly to Project_3).

    • 3) Print to terminal the TOTAL number of sensors built to equip the agency’s car fleet

(total number by sensor type).

    • 4) Find the most expensive available car – ask the user if they want to rent it – update that car’s lessee and availability status if the user says yes.

    • 5) Exit program.




The following minimum functionality and structure is required:
    • Ask the user for the input file name.

    • The list of Sensors must be stored in an array of Objects.

    • The list of Cars must be stored in an array of Objects.

    • Use character arrays to hold your strings (i.e., C-style) exclusively (using the string data type is still not allowed).

    • Write multiple functions (Hint: You could have each menu option be a function).

    • At least one function must use Pass-by-Reference.

    • At least one function must use Return-by-Reference.

    • Otherwise, as before, you are free to use pass by-Value, pass by-Reference, pass by-Address for your function parameters.

    • Variables, data members, functions, function signatures, should almost all be made const in a perfect design, unless there is no other way for the program to work. (This might seem as an overstatement. However, try to remember the const keyword and design around it as much as you can). You are required to at least try.

    • Pointers must be used for all array manipulation (iterating over elements to read/modify cannot be performed with bracket operator accessing). The only exception on [] is if you are using your own overload of operator[].

    • Pointers must be used in function prototypes and function parameter lists (the bracket notation is not allowed in parameters lists).Pointers can only be moved by incrementing or decrementing:

double d[3] = {1,2,3}; double * d_Pt = d;
for (int i=0; i<3; ++i,++d_Pt){ cout << *d_Ptd; }

    • Or by setting the pointer back to the base address using the array name. d_Pt = d; cout << *d_Pt << endl;

    • Write your own C-string length, compare, copy, concatenate functions. Their prototypes will have the form (use the prototypes exactly as provided, with char * parameters):

        ◦ counts characters in str array until a NULL-character '\0' is found, then it returns that number excluding the '\0' one

        ◦ the return type size_t represents an unsigned integral number large enough to contain the maximum possible number of a storage size that can appear on a target architecture

size_t myStringLength(const char * str);

    • returns 0 when the C-strings match, i.e. their characters are equal one-by-one until a NULL-character '\0' is found in both strings and at the same position as well

    • returns a value <= -1 if the first character that does not match has a lower value in str1 than in str2

    • returns a value >= 1 if the first character that does not match has a higher value in str1 than in str2

int myStringCompare(const char * str1, const char * str2);

    • copies characters from source to destination array until a NULL-character '\0' is found in source, then it NULL-terminates destination too

    • returns a pointer to the destination array

char * myStringCopy(char * destination, const char * source);

    • appends the content of source to the destination array

    • this means that the NULL-terminator of destination is overwritten by the first character of source and a NULL-character '\0' is appended at the end of the concatenated Cstring in destination

    • returns a pointer to the destination array

char * myStringCat(char * destination, const char * source);

    • The other functionality and structure of the program should remain the same as Project #3, including writing to screen and file, as well as restrictions on string libraries, global variables and constants, etc.

Implement the concepts of encapsulation and data hiding (required)!
Use the const keyword where appropriate (almost everywhere you can make it work)!
Implement Class Constructors with Initializer-Lists (advised)!

Implement operator overloads (required)!

This is a chance to experiment as much as possible with more advanced concepts and the intricacies of classes. It is not a strict requirement that const data members which can only be instantiated with a list initialization are there in your code right now. Try your best in order to acquaint yourself with the new concepts of this Project however, and figure out what might be giving you a hard time understanding and/or implementing at this early point.

The completed project should have the following properties:
    • Written, compiled and tested using Linux.

    • It must compile successfully using the g++ compiler on department machines. Instructions how to remotely connect to department machines are included in the Projects folder in WebCampus.

    • The code must be commented and indented properly.

Header comments are required on all files and recommended for the rest of the program. Descriptions of functions commented properly.

    • A one page (minimum) typed sheet documenting your code. This should include the overall purpose of the program, your design, problems (if any), and any changes you would make given more time.

Turn in: Compressed .cpp and .h files and project documentation.
Submission Instructions:
    • You will submit your work via WebCampus

    • Name your code file proj4.cpp

    • If you have header file, name it proj4.h

    • If you have class header and source files, name them as the respective class (Sensor.h, Sensor.cpp, Car.h, Car.cpp, Agency.h, Agency.cpp). This source code structure is mandatory at this point.

    • Compress your:

        1. Source code

        2. Documentation

    • Name the compressed folder: PA#_Lastname_Firstname.zip

([PA] stands for [ProjectAssignment], [#] is the Project number) Ex: PA4_Smith_John.zip


Verify: After you upload your .zip file, re-download it from WebCampus. Extract it, compile it and verify that it compiles and runs on the NoMachine virtual machines or directly on the ECC systems.

    • Code that does not compile will be heavily penalized –may even cost you your entire grade–. Executables that do not work 100% will receive partial grade points.

    • It is better to hand in code that compiles and performs partial functionality, rather than broken code. You may use your Documentation file to mention what you could not get to work exactly as you wanted in the given timeframe of the Project.

Late Submission:

A project submission is "late" if any of the submitted files are time-stamped after the due date and time. Projects will be accepted up to 24 hours late, with 20% penalty.