Car Class with Dynamic Memory

Question

What To Code

With your Car class from previous code:

1. Rewrite the C string members (make and model) to be dynamic C strings.

Make all C strings the length of any passed in C string.

NOTE: The other variables (including temporary C strings used only in functions) don't need to be made dynamic.

2. Write a destructor for this class that deletes the dynamic C-Strings.

3. Write a public member function called 'print' that prints out the make, model and year values.

Use carmain2.cpp to test your class. note that it passes in constant C strings so make your class setters take a const C string:

void setMake(const char *mk);

and also make the getters' return type a constant:

const char * getMake();

Requirements

• Must have dynamic C-Strings as member variables in your Car class. No static C strings or string type variables.

• Must have a destructor for your class.

• Must have 2files: car.h and car.cpp

• No function definitions in the car.h file.

EXAMPLE OUTPUT #1

--------------------------------

Sedan before initialization:

make: <no value set>

model: <no value set>

year: 0

Compact values

Make: Honda

Model: Civic

Year: 2017

Setting values for sedan:

Enter make: Ford

Enter model: Escort

Enter year: 1997

printing values for sedan:

Make: Ford

Model: Escort

Year: 1997

carmain2.cpp:

#include "car.h"

#include<iostream>

using namespace std;

int main()

{

  Car sedan;

// input

string imake;

string imodel;

int iyear;

// output

string omake;

string omodel;

int oyear;

// getting values before setting them.

// This may produce garbage values. We will be

// fixing this in exercise 2.

cout << "Sedan before initialization: " << endl;

omake = sedan.getMake();

cout << "Make: " << omake << endl;

omodel = sedan.getModel();

cout << "Model: " << omodel << endl;

oyear = sedan.getYear();

cout << "Year: " << oyear << endl;

//set the values for sedan

cout << "Setting values for sedan: " << endl;

cout << "Enter make: ";

getline(cin, imake);

sedan.setMake(imake);

cout << "Enter model: ";

getline(cin, imodel);

sedan.setModel(imodel);

cout << "Enter year: ";

cin >> iyear;

cin.ignore(200, '\n');

sedan.setYear(iyear);

// getting the data back out

cout << "printing values for sedan: " << endl;

omake = sedan.getMake();

cout << "Make: " << omake << endl;

omodel = sedan.getModel();

cout << "Model: " << omodel << endl;

oyear = sedan.getYear();

cout << "Year: " << oyear << endl;

return 0;

}

Answer 1

#ifndef _CAR

#define _CAR

typedef

class Car

{

protected:

char * carMake;

char * carModel;

int carYear;

public:

Car(char * make, char * model, int yr);

Car(const Car&);

~Car();

void SetCarMake( char * make);

void SetCarModel(char * model);

void SetCarYear(int yr);

int GetCarMakeLength();

int GetCarModelLength();

char * GetCarMake(char *);

char * GetCarModel(char *);

int GetCarYear();

void Print(char *strMsg=(char*)0);

} * TCar;

#define CAR_SIZE (sizeof(Car))

#endif

//********************************************************************************************//

#ifndef _CAR

#include "Car.h"

#endif

#include

#include

#include

void Car::SetCarMake( char * make)

{

int nStrLen = strlen(make)+1;

this->carMake = (char *)malloc(nStrLen+1);

strcpy(this->carMake,make);

}

void Car::SetCarModel(char * model)

{

int nStrLen = strlen(model)+1;

this->carModel = (char *)malloc(nStrLen+1);

strcpy(this->carModel,model);

}

void Car::SetCarYear(int yr)

{

this->carYear = yr;

}

Car::Car(char * make, char * model, int yr)

{

this->SetCarMake(make);

this->SetCarModel(model);

this->SetCarYear(yr);

}

Car::Car(const Car& car)

{

this->SetCarMake(car.carMake);

this->SetCarModel(car.carModel);

this->SetCarYear(car.carYear);

}

Car::~Car()

{

if (this->carMake!=NULL) { free(this->carMake); }

if (this->carModel!=NULL) { free(this->carModel); }

}

int Car::GetCarMakeLength() { return( strlen(this->carMake) +1); }

int Car::GetCarModelLength(){ return( strlen(this->carModel)+1); }

char * Car::GetCarMake(char * buff) { strcpy(buff,this->carMake); return(buff); }

char * Car::GetCarModel(char * buff) { strcpy(buff,this->carModel); return(buff); }

int Car::GetCarYear(){ return(carYear); }

void Car::Print(char *strMsg)

{

if (strMsg!=NULL)

{

printf("********************************************************************\n");

printf(strMsg);

}

printf("********************************************************************\n");

printf(" Make = >%s< \n",this->carMake);

printf(" Model = >%s< \n",this->carModel);

printf(" year = %d \n",this->carYear);

}