I'm having a problem understanding vectors of pointers to class objects, I tried a test code to try and understand it but whenever I enter a name and try to output it, it prints out numbers instead of the actual name that I entered. I'm hoping someone can explain this to me as I'm new to these concepts.
Also
Pets[0]->print(); dosent print at all while:
cout << "in main: " << Pets[0] << endl;
prints.
class Pet
{
public:
string name;
Pet(const string&);
string getName() const
{
return name;
}
void setName(const string& Name)
{
name = Name;
}
void print()const;
}
int main()
{
vector<Pet*> Pets;
string names;
int done = NULL;
do
{
{
cout << "Name: ";
cin >> names;
Pets.push_back(new Pet(names));
cin.ignore();
}
cout << "Add another ?" << endl;
cin >> done;
} while (done != 0);
Pets[0]->print();
cout << "in main: " << Pets[0] << endl;
system("pause");
}
Pet::Pet(const string& Name)
{
}
void Pet::print()const
{
cout << "Name: " << name;
}
The constructor of Pet does not assign the parameter, hence it remains empty.
Write...
Pet::Pet(const string& Name) : name(Name) { }
to do this initialization.
Related
The code compiles it does not read staff.txt. Not sure how to fix in the code. the error must be in reading the staff.txt of the code. Does anyone have an idea? output is in the image provided. Background on the question:
You are tasked to create 2 ADTs: customers and staff. Each customer will have a first and last name, an indication if the customer is enrolled in the “preferred” program, the car they are driving, and the amount of money owed to the company. On the other hand, each staff member will have a first and last name, the car they are driving, and their salary. In a real-world problem, there would obviously be more records associated with each staff member and customer.
ODU rentals would like you to automatically process txt files and print the information to the console screen. When you perform this process, ensure that your member variables are private. In addition, be sure to use getter and setter functions to manipulate and print your data. You may print your data in any format as long as it is organized. An example of correct output can be seen below.
#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>
#include <cstdlib>
using namespace std;
class Customer {
string fname;
string lname;
int enroll;
string car;
float amount;
public:
//Defining the customer ADT
Customer();
void setFirstName(string fnm);
void setLastName(string lnm);
void setEnroll(int e);
void setCarName(string cnm);
void setAmount(float amt);
string getFirstName();
string getLastName();
int getEnroll();
string getCarName();
float getAmount();
void printData();
};
Customer::Customer() {
fname = lname = car = "";
enroll = 0;
amount = 0;
}
void Customer::setFirstName(string fnm) {
fname = fnm;
}
void Customer::setLastName(string lnm) {
lname = lnm;
}
void Customer::setEnroll(int e) {
enroll = e;
}
void Customer::setCarName(string cnm) {
car = cnm;
}
void Customer::setAmount(float amt) {
amount = amt;
}
string Customer::getFirstName() {
return(fname);
}
string Customer::getLastName() {
return(lname);
}
int Customer::getEnroll() {
return(enroll);
}
string Customer::getCarName() {
return(car);
}
float Customer::getAmount() {
return(amount);
}
void Customer:: printData() {
cout << left << setw(25) << getFirstName()+" "+getLastName() << left <<setw(15) << getEnroll();
cout << left << setw(15) << getCarName() << left << setw(15) << fixed << setprecision(2) << getAmount() << endl;
}
class Staff {
string fname;
string lname;
string car;
float salary;
public:
//Defining staff ADT
Staff();
void setFirstName(string fnm);
void setLastName(string lnm);
void setCarName(string cnm);
void setSalary(float sal);
string getFirstName();
string getLastName();
string getCarName();
float getSalary();
void printData();
};
Staff::Staff() {
fname = lname = car = "";
salary = 0;
}
void Staff::setFirstName(string fnm) {
fname = fnm;
}
void Staff:: setLastName(string lnm) {
lname = lnm;
}
void Staff::setCarName(string cnm) {
car = cnm;
}
void Staff::setSalary(float sal) {
salary = sal;
}
string Staff::getFirstName() {
return(fname);
}
string Staff::getLastName() {
return(lname);
}
string Staff::getCarName() {
return(car);
}
float Staff::getSalary() {
return(salary);
}
void Staff:: printData() {
cout << left << setw(25) << getFirstName()+" "+getLastName() << left << setw(15);
cout << getCarName() << left << setw(15) << fixed << setprecision(2) << getSalary() <<endl;
}
//Main function
//Read txt files
int main() {
string fnm, lnm, carnm;
float amt, sal;
int e, i=0, recno;
ifstream fstaff("staff.txt");
if(!fstaff) {
cout << "File can not be opened" << endl;
exit(1);
}
fstaff >> recno;
Staff s[recno];
cout << left<<setw(25) << "Name" << left << setw(15) << "Car" << left << setw(15) << "Salary" <<endl;
cout << "____________________________________________________________________________" << endl;
for(i=0; i<recno; i++) {
fstaff>>fnm>>lnm>>carnm>>sal;
s[i].setFirstName(fnm);
s[i].setLastName(lnm);
s[i].setCarName(carnm);
s[i].setSalary(sal);
s[i].printData();
}
fstaff.close();
ifstream fcust("customers.txt");
if(!fcust) {
cout << "File can not be opened"<<endl;
exit(1);
}
fcust >> recno;
Customer c[recno];
cout << endl << endl;
cout << left << setw(25) << "Name" << left << setw(15) << "Preferred" << left << setw(15) << "Car" << left << setw(15) << "Bill" << endl;
cout <<"____________________________________________________________________________"<<endl;
for(i=0; i<recno; i++) {
fcust >> fnm >> lnm >> e >> carnm >>amt;
c[i].setFirstName(fnm);
c[i].setLastName(lnm);
c[i].setEnroll(e);
c[i].setCarName(carnm);
c[i].setAmount(amt);
c[i].printData();
}
fcust.close();
return 1;
}
Code Output
This question already has answers here:
Undefined reference to static variable c++
(3 answers)
Closed 2 years ago.
I created a Class Student with instance data members
like studentname, studentaddress, studentrollno
i declared private static data member CollegeName that could be shared among all instances of class.
used promptfunction to take user input from the console
next functions to display student details.
Meanwhile resulting in below errors :
Meanwhile codes goes here:
#include <iostream>
#include <string>
using namespace std;
class Student {
private:
int studentrollno;
string studentName;
string studentAddress;
static string CollegeName;
public:
void setRollNo(int rollno) {
studentrollno = rollno;
}
int getRollNo() {
return studentrollno;
}
void setName(string name) {
studentName = name;
}
string getName() {
return studentName;
}
void setAddress(string address) {
studentAddress = address;
}
string getAddress() {
return studentAddress;
}
static void setCollegeName(string collegename) {
CollegeName = collegename;
}
static string getCollegeName() {
return CollegeName;
}
void displayStudentDetails(); // member functions declare inside class Meanwhile it is defined
outside
static void show() {
cout << "this is static function " << endl;
}
};
// member functions define outside Student class
void Student :: displayStudentDetails() {
cout << "Student Name : " << getName() << " Student RollNo : " << getRollNo() << "Student Address
: " << getAddress() << "CollegeName: "<< getCollegeName() << endl;
}
void promptValues(Student &student) {
cout << "Enter the student Details " << endl;
cout << "Enter the details about student objects " << endl;
cout << endl;
int studentrollno;
string studentname , studentaddress ;
string collegename;
cout << "Enter the RollNo of the student " << endl;
cin >> studentrollno;
cout << "Enter the Name of the student " << endl;
cin >> studentname;
cout << endl;
cout << "Enter the address of the student " << endl;
cin >> studentaddress;
cout << endl;
cout << "Enter the collegeName of the student " << endl;
cin >> collegename;
student.setRollNo(studentrollno), student.setName(studentname), student.setAddress(studentaddress),
student.setCollegeName(collegename);
}
int main() {
Student student1, student2 , student3 , student4 , student5 ;
Student studentarrays[5] = { student1, student2, student3, student4, student5 };
Student studentmodel[5];
for (int i = 0; i < 5; i++) {
Student model;
model = studentarrays[i];
promptValues(model);
studentmodel[i] = model;
}
for (Student studentdetails : studentmodel) {
studentdetails.displayStudentDetails();
}
Student::show();
return 0;
}
You have omited the definition of the static member Student::CollegeName. It is only declared in the class, now you should define it after the class declaration with this:
std::string Student::CollegeName;
For more information see https://en.cppreference.com/w/cpp/language/static
When i run this program it get fatal error and program got stopped. I think this problem is due to string type of may be using std::string. because when i use char data type it was runs correctly. What is the problem kindly guide.
parcel.cpp
#include "Parcel.h"
#include <iostream>
#include <string>
using namespace std;
bool check = false;
// Constructor
Parcel::Parcel(int id, std::string senderName, std::string senderAddress, std::string receiverName, std::string receiverAddress, int weight, int fee){
this->id = id;
this->senderName = senderName;
this->senderAddress = senderAddress;
this->receiverName = receiverName;
this->receiverAddress = receiverAddress;
this->weight = weight;
this->fee = fee;
};
// Destructor
Parcel::~Parcel() {
cout << "Destructor called";
}
// Defination of setter
void Parcel::setID(int id) {
this->id = id;
if(id < 0) {
cout << endl << "Error: Please write valid receipt number e.g. 0 to onward";
}
}
void Parcel::setWeight(int weight) {
this->weight = weight;
if(weight < 0) {
cout << endl << "Error: Please write valid weight e.g. above to 0 grams";
}
}
void Parcel::setFee(int fee) {
this->fee = fee;
if(fee < 0) {
cout << endl << "Error: Please write valid fee e.g. 0 to onward";
}
}
void Parcel::setSenderName(std::string senderName) {
this->senderName = senderName;
// if(strlen(senderName) == 0) {
// cout << endl << "Error: Please write sender name";
// }
}
void Parcel::setSenderAddress(std::string senderAddress) {
this->senderAddress = senderAddress;
// if(senderAddress == 0) {
// cout << endl << "Error: Please write sender address";
// }
}
void Parcel::setReceiverName(std::string receiverName) {
this->receiverName = receiverName;
// if(receiverName == 0) {
// cout << endl << "Error: Please write reciever name";
// }
}
void Parcel::setReceiverAddress(std::string receiverAddress) {
this->receiverAddress = receiverAddress;
// if(receiverAddress == 0) {
// cout << endl << "Error: Please write reciever address";
// }
}
// Defination of getter
int Parcel::getID() {
return id;
}
int Parcel::getWeight() {
return weight;
}
int Parcel::getFee() {
return fee;
}
string Parcel::getSenderName() {
return senderName;
}
string Parcel::getSenderAddress() {
return senderAddress;
}
string Parcel::getReceiverName() {
return receiverName;
}
string Parcel::getReceiverAddress() {
return receiverAddress;
}
parcel.h
#ifndef PARCEL_H
#define PARCEL_H
#include <iostream>
#include <string>
class Parcel
{
private:
// Declare data members
int id, weight, fee;
std::string senderName, senderAddress, receiverName, receiverAddress;
public:
// Setter function
void setID(int id);
void setWeight(int weight);
void setFee(int fee);
void setSenderName(std::string senderName);
void setSenderAddress(std::string senderAddress);
void setReceiverName(std::string receiverName);
void setReceiverAddress(std::string receiverAddress);
// getter function
int getID();
int getWeight();
int getFee();
std::string getSenderName();
std::string getSenderAddress();
std::string getReceiverName();
std::string getReceiverAddress();
// Constructor
Parcel(int id, std::string senderName, std::string senderAddress, std::string receiverName, std::string receiverAddress, int weight, int fee);
// Destructor
~Parcel();
protected:
};
#endif
main.cpp
#include <iostream>
#include "Parcel.h"
#include <string>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
using namespace std;
// Data member to take input from user
int id, weight, fee;
std::string senderName, senderAddress, receiverName, receiverAddress;
// main function
int main(int argc, char** argv) {
cout << "Please enter receipt number: ";
cin >> id;
cout << "Please enter sender name: ";
cin >> senderName;
cout << "Please enter sender address: ";
cin >> senderAddress;
cout << "Please enter receiver name: ";
cin >> receiverName;
cout << "Please enter receiver address: ";
cin >> receiverAddress;
cout << "Please enter parcel weight(gms): ";
cin >> weight;
cout << "Please enter parcel fee: ";
cin >> fee;
// Instance of Parcel class
Parcel parcel(parcel.getID(), parcel.getSenderName(), parcel.getSenderAddress(), parcel.getReceiverName(), parcel.getReceiverAddress(), parcel.getWeight(), parcel.getFee());
// Set values
parcel.setID(id);
parcel.setSenderName(senderName);
parcel.setSenderAddress(senderAddress);
parcel.setReceiverName(receiverName);
parcel.setReceiverAddress(receiverAddress);
parcel.setWeight(weight);
parcel.setFee(fee);
// Make output to show on console
cout << endl << endl;
cout << "Shipment Receipt" << endl << "___________________________________________" << endl;
cout << "Receipt No.: " << parcel.getID() << endl << "Sender Name: " << parcel.getSenderName() << endl
<< "Sender Address: " << parcel.getSenderAddress() << endl << "Receiver Name: " << parcel.getReceiverName() << endl
<< "Receiver Address: " << parcel.getReceiverAddress() << endl << "Parcel Weight: " << parcel.getWeight() << endl
<< "Parcel Shipping Charges: " << parcel.getFee() << endl;
// Destructor call
parcel.~Parcel();
}
Parcel parcel(parcel.getID(), parcel.getSenderName(), parcel.getSenderAddress(), parcel.getReceiverName(), parcel.getReceiverAddress(), parcel.getWeight(), parcel.getFee());
Don't do that. You are calling parcel.getSenderName() before the parcel object is fully initialized.
Your program doesn't terminate with instance of bad alloc when I tried to run. However, it does get warnings because of this line
Parcel parcel(parcel.getID(), parcel.getSenderName(), parcel.getSenderAddress(), parcel.getReceiverName(), parcel.getReceiverAddress(), parcel.getWeight(), parcel.getFee());
You should consider a default constructor Parcel() with default values assigned to different attributes and then Parcel parcel before assigning them in main()
What arguments did you run your program with?
Your construction,
Parcel parcel(parcel.getID(), parcel.getSenderName(), parcel.getSenderAddress(), parcel.getReceiverName(), parcel.getReceiverAddress(), parcel.getWeight(), parcel.getFee());
initialises parcel with itself, which is uninitialised.
This is undefined, and anything can happen.
You've already read all parameters from the user, so use them:
Parcel parcel(id, senderName, senderAddress, receiverName, receiverAddress, weight, fee);
You can remove the entire sequence of setters.
And you should not call the destructor; C++ handles destruction automatically.
If you found that idea in a book, throw it away immediately and look for a better one here.
If you don't have a book, look in the same place.
Im trying to create a percent savings program for a supermarket with 3 inherited classes (PersonData -> CustomerData -> PreferredCustomer). The entire program has to follow this UML diagram:
I am having problems with the third class; specifically initializing values in the first constructor of the class. Im getting an error message in visual studio: "redefinition of formal parameter Pa" and "redefinition of formal parameter "dl".
This is the constructor with the errors:
PreferredCustomer(string aLname, string aFname, string aAddress,
string aCity, string aState, int aZip, string aPhone, int cn,
bool ml, double Pa, double dl) // constructor 1
{
double Pa;
double dl;
}
The parameters in this third child constructor have been overloaded from the parent constructor. Arguments cn, ml, Pa, dl have all been added into this parameter.
I'm not sure why i am getting these errors? Also, should i be creating a virtual function or using pointers? Thank you for any help.
My program source code (for reference):
#include <iostream>
#include <string>
using namespace std;
class PersonData // PersonData parent class defined
{
private:
string lastName;
string firstName;
string address;
string city;
string state;
string phone;
int zip;
public:
PersonData() // Default Constructor initialization
{
lastName = " ";
firstName = " ";
address = " ";
city = " ";
state = " ";
zip = 0;
phone = " ";
}
PersonData(string aLname, string aFname, string aAddress, string aCity, string aState, int aZip, string aPhone) // Constructor 1
{
lastName = aLname;
firstName = aFname;
address = aAddress;
city = aCity;
state = aState;
zip = aZip;
phone = aPhone;
}
// Accesor Functions
string getLastName() const
{
return lastName;
}
string getFirstName() const
{
return firstName;
}
string getAddress() const
{
return address;
}
string getCity() const
{
return city;
}
string getState() const
{
return state;
}
int getZip() const
{
return zip;
}
string getPhone() const
{
return phone;
}
// Mutator Functions
void setLastName(string aLname)
{
lastName = aLname;
}
void setFirstName(string aFname)
{
firstName = aFname;
}
void setAddress(string aAddress)
{
address = aAddress;
}
void setCity(string aCity)
{
city = aCity;
}
void setState(string aState)
{
state = aState;
}
void setZip(int aZip)
{
zip = aZip;
}
void setPhone(string aPhone)
{
phone = aPhone;
}
};
class CustomerData :public PersonData // CustomerData child class of PersonData base class
{
private:
int customerNumber;
bool mailingList;
public:
CustomerData() // Default constructor
{
customerNumber = 0;
mailingList = 0;
}
CustomerData(int cNum, bool mailL) // Constructor 1
{
setCustomerNumber(cNum);
setMailingList(mailL);
}
// Accessor Functions for child class
int getCustomerNumber() const
{
return customerNumber;
}
bool getMailingList() const
{
if (mailingList != 0)
{
cout << "On Mailing List!: ";
return mailingList;
}
else (mailingList == 0);
{
cout << "Not on mailing list!: ";
return mailingList;
}
}
// Mutator Functions for child class
void setCustomerNumber(int cNum)
{
customerNumber = cNum;
}
void setMailingList(bool mailL)
{
mailingList = mailL;
}
};
class PreferredCustomer :public CustomerData // child class of CustomerData child class
{
private:
double purchasesAmount;
double discountLevel;
public:
PreferredCustomer() // default constructor
{
purchasesAmount = 0;
discountLevel = 0;
}
PreferredCustomer(string aLname, string aFname, string aAddress,
string aCity, string aState, int aZip, string aPhone, int cn,
bool ml, double Pa, double dl) // constructor 1
{
double Pa;
double dl;
}
// Mutator Functions
void setPurchasesAmount(double Pa)
{
purchasesAmount = Pa;
}
// Accessor Functions
double getPurchasesAmount() const
{
return purchasesAmount;
}
double getDiscountLevel() const
{
return discountLevel;
}
void addPurchase(double P) const
{
}
};
int main()
{
CustomerData Cdata; // for access of child class functions
PersonData Pdata; // for access of parent class functions
PreferredCustomer PCdata; // for access of preferred customer class functions
string temp1; // Temporary variable for string values
int temp2, // Temporary variable for integer values
max = 100, // For-loop maximum loop value
i; // i variable
bool temp3; // Temporary variable for bool values
for (i = 1; i <= max; i++)
{
// Input Data
cout << "Please input first Name: ";
getline(cin, temp1);
Pdata.setFirstName(temp1);
cout << "Please input last Name: ";
getline(cin, temp1);
Pdata.setLastName(temp1);
cout << "Please input address: ";
getline(cin, temp1);
Pdata.setAddress(temp1);
cout << "Please input city: ";
getline(cin, temp1);
Pdata.setCity(temp1);
cout << "Please input state: ";
getline(cin, temp1);
Pdata.setState(temp1);
cout << "Please input Zip code: ";
cin >> temp2;
Pdata.setZip(temp2);
cin.ignore(); // discards unread char from cin
cout << "Please input Phone Number: ";
getline(cin, temp1);
Pdata.setPhone(temp1);
cout << "Enter 1 to be included in mail list," << endl;
cout << "Enter 0 to not be included in mail list: ";
cin >> temp3;
Cdata.setMailingList(temp3);
Cdata.setCustomerNumber(i); // set customer number
cout << endl << endl;
cout << "Name: " << Pdata.getFirstName() << ", " << Pdata.getLastName() << " \n";
cout << "Customer Number: " << Cdata.getCustomerNumber() << "\n";
cout << "Address: " << Pdata.getAddress() << "\n";
cout << "City: " << Pdata.getCity() << "\n";
cout << "State: " << Pdata.getState() << "\n";
cout << "Phone: " << Pdata.getPhone() << "\n";
cout << "Zip: " << Pdata.getZip() << "\n";
cout << Cdata.getMailingList() << "\n";
cout << endl << endl;
cin.ignore(); // discards unread char from cin
}
char c;
cin >> c;
return 0;
}
A constructor's purpose is to take the parameters the are passed in and construct the object from the class declaration and initialize members as appropriate. It not only has to initialize the class but also all the base classes as well, this can be done by passing parameters to the base constructor(s).
In
PreferredCustomer(string aLname, string aFname, string aAddress,
string aCity, string aState, int aZip, string aPhone, int cn,
bool ml, double Pa, double dl) // constructor 1
{
double Pa;
double dl;
}
You aren't initializing anything
You are declaring two local parameters that match (and conflict with) the parameters passed in
You don't call the base's constructors (how most of the work is done)
PreferredCustomer(...) :CustomerData(...)
CustomerData(...) :PersonData(...)
You don't initialize this class's members
purchasesAmount = pa;
discountLevel = dl;
This is a follow up to my previous question. I have some code which should be running fine, and it does for the most part. When I run it, most of the main method runs but I get a segmentation fault when the getter methods are executed. Here is the code:
#include <iostream>
#include <string>
using namespace std;
class Person
{
protected:
string m_FirstName, m_LastName, m_email;
public:
Person(){}
Person(const string& firstName, const string& lastName) :
m_FirstName(firstName), m_LastName(lastName)
{}
string get_name() const
{
return m_FirstName;
}
string get_surname() const
{
return m_LastName;
}
bool has_email_p()
{
}
};
class Person_with_telephone: public Person
{
protected:
string m_telephone;
public:
Person_with_telephone(){}
Person_with_telephone(const string& telephone) : m_telephone(telephone)
{}
bool has_telephone_p()
{
if (m_telephone == "")
{
cout << "You have no phone number registered" << endl;
return false;
}
else
{
cout << "Your number is: " << m_telephone << endl;
return true;
}
}
string get_telephone() const
{
return m_telephone;
}
string set_telephone()
{
}
string get_telephone()
{
}
};
int main()
{
string f, l, ph;
cout << "Enter fist name: ";
cin >> f;
cout << "Enter Last name: ";
cin >> l;
cout << "Enter telephone number: ";
cin >> ph;
Person p(f, l);
Person_with_telephone pwt(ph);
cout << "Your name is: " << p.get_name() << " " << p.get_surname() << endl;
cout << "Has telephone? " << endl << " Your number is: " << pwt.get_telephone() << endl;
return 0;
}
When I compile it compiles fine and when I run I get asked for the three inputs of Name, Surname and Telephone, but when I input the last value I get this:Odd segfault
You are not returning anything in Person_with_telephone::get_telephone(). This will cause a segfault.
If you compile with proper warnings turned on Then you should at least get
main.cpp:32:9: warning: control reaches end of non-void function [-Wreturn-type]
}
^
main.cpp:69:3: warning: control reaches end of non-void function [-Wreturn-type]
}
^
main.cpp:74:3: warning: control reaches end of non-void function [-Wreturn-type]
}
^
3 warnings generated.
Which would let you know that you need return statements in those functions.
Your bool has_email_p(), string get_telephone() and string set_telephone() functions don't do or, more importantly, return anything.