I'm new in oop and don't know how to specify this problem globally. I have two classes. Client
class Client
{
private:
int code;
string name;
public:
Client(int c, string n);
int getCode();
string getName();
};
Client::Client(int c, string n)
{
this->code = c;
this->name = n;
}
int Client::getCode()
{
return this->code;
}
string Client::getName()
{
return this->name;
}
and Account
class Account
{
private:
int number;
double balance;
double interestRate;
Client* owner;
};
and I have method like this:
Client* Account::getOwner()
{
return this->something;
}
Can you please tell me, how can I get client's code and name from this method?
Can you please tell me, how can I get client's code and name from this method?
The method is called getOwner. A method called getOwner should ... get ... the owner. Nothing else.
If you want to get the owner's name, either write a new method
string getOwnerName() const { return owner->getName(); }
or ...
(better because it reduces coupling between the Account and Client classes, possibly worse because it depends on exposing the owner directly, but then you're already doing that ...)
... just delegate this to the client code:
cout << account->getOwner()->getName();
Related
New to classes and objects in c++ and trying to learn a few basics
I have the class TStudent in which the Name, Surname and Age of student are stored, also I have the constructor which is accessed in main and inserts in the data.
What I want to do is: having the class TRegistru, I have to add my objects data in it, in a way that I can store it there, then I could save the data in data.bin and free the memory from the data, then I want to put the data back in the class and print it out.
The question is: In what way & what is the best way to add my objects in the second class, so that I could eventually work with them in the way I've described in the comments, so that I won't have to change nothing in main
Here's my code so far:
#include <iostream>
using namespace std;
class TStudent
{
public:
string Name, Surname;
int Age;
TStudent(string name, string surname, int age)
{
Name = name;
Surname = surname;
Age = age;
cout <<"\n";
}
};
class TRegistru : public TStudent
{
public:
Tregistru()
};
int main()
{
TStudent student1("Simion", "Neculae", 21);
TStudent student2("Elena", "Oprea", 21);
TRegistru registru(student1);//initialising the object
registru.add(student2);//adding another one to `registru`
registru.saving("data.bin")//saving the data in a file
registru.deletion();//freeing the TRegistru memory
registru.insertion("data.bin");//inserting the data back it
registru.introduction();//printing it
return 0;
}
Hence the question is about passing data from A to B, I will not comment on the file handling portion.
This can be done in multiple ways, but here is one of the simplest and most generic. By calling TRegistru::toString() you serialize every TStudent added to TRegistru into a single string which then can be easily written to a file.
Demo
class TStudent
{
public:
std::string Name, Surname;
int Age;
std::string toString() const
{
return Name + ";" + Surname + ";" + to_string(Age);
}
};
class TRegistru
{
public:
void add(const TStudent& student)
{
students.push_back(student);
}
void deletion()
{
students.clear();
}
std::string toString() const
{
std::string ret{};
for(const auto& student : students)
{
ret += student.toString() + "\n";
}
return ret;
}
std::vector<TStudent> students;
};
I was working on homework that my instructor wanted me to write a class named Species with setter and getter functions. I wrote that code but I can't set or get any value when I run it. Can you help me?
class Species
{
private:
string name;
string country;
int population;
int growthrate;
public:
int year;
void setName(string NameS){
NameS=name;
}
void setCountry(string CountryS){
CountryS=country;
}
void setPopulation(int pop){
pop=population;
}
void setGrowthRate(int GrowRth){
GrowRth=growthrate;
}
void setYear(int syear){
syear=year;
}
string getName() {
return name;
}
string getCountry() {
return country;
}
int getPopulation() {
return population;
}
int getGrowthrate() {
return growthrate;
}
double e=2.71828182;
double calculatePopulation() {
int b=growthrate*year;
int a=pow(e,b);
return population*a;
}
};
First of all. Your class has fields like:
string name;
string country;
int population;
int growthrate;
And your methods are like:
void setName(string NameS){
NameS=name;
}
So you want to set NameS value to the name which makes no sense.
You should assign the field like name to be equal to nameS not the opposite.
Generally, a setter should look like this.
void setVariable(const VariableType& var){
this->var=var;
}
What you did was var=this->var.
Btw, you should make your getter-s const
You should use "this" keyword to set the value to object of the class.
this: to refer current class instance variable. The this keyword can be used to refer current class instance variable.
for example:
void setName(string name){
this.name=name;
}
void setGrowthRate(int growthrate){
this.growthrate=growthrate;
"this" is very helpful in please learn more about it.
I have a basic class ContactDetails which has a private variables as string name and string address. This ContactDetails data structure is used in my program for all entities. For some entities, I need other info on top of name and address, such as phone number, pin code etc. How to design the class.
class ContactDetails {
private:
std::string name;
std::string address;
public:
ContactDetails() {
this->name = "";
this->address = "";
}
std::string getName() { return name; }
std::string getAddress() { return address; }
void setName(std::string n) { name = n; }
void setAddress(std::string n) { address = n; }
}
class ContactDetailsHelper {
public:
ContactDetails getX() {
ContactDetails obj;
obj.setName("X");
obj.setAddress("New York");
return obj;
}
ContactDetails getY() {
//Y has phone number, pin code, county code etc details available.
ContactDetails obj;
obj.setName("Y");
obj.setAddress("Chicago");
//need to set more details in the object
return obj;
}
If we take phone number, pin code, county code as a private member in ContactDetails class, most of the time it would be empty. So how to design the class in such a way like extra details we could put it in another class and if needed for any entity we could use them.
I am new to C++ programming and I need to create an object and name it with a string written on keyboard. However I tried to use pointers and variables, but when I declare an object (let’s say an int) there is no way to give its name after something written by user. I’ll do my best to picture that, forgive me for being so simple.
int main() {
string x;
std::cin>>x;
int x;
}
I would like to create an int object whose name is the string x previously declared and filled by user on keyboard. However this gives me an error, clearly, and pointers do not seem to work. Is there any other way? Thank you all in advance.
class A{
public:
A(){}
A(std::string _name): name{_name}{}
void setName(std::string _name)
{
name = _name;
}
std::string name;
}
this is how you object can look like.
you can creat it like this
int main()
{
string x;
std::cin>>x;
A a(x); //one option;
A b;
b.setName(x);//second option
}
Okay, so I have an assignment for a class that requires us to use a series of classes together, to simulate a police officer issuing a ticket.
Here's how it works:
ParkedCar class:
To know the cars make, model, color, license number, and the number of minutes
that the car has been parked
ParkingMeter Class:
know how much time has been purchased
ParkingTicket Class:
know make, model, color, license of the car, calculate the fine, as well as the name and badge number of the officer issuing the ticket
PoliceOfficer Class:
Know the name a badge number of the officer
AND
Examine ParkedCar and ParkingMeter objects and determine if a ticket is needed, if so, generate a ParkingTicket object.
Here's what code I have so far:
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<ctime>
using namespace std;
class ParkedCar
{
string sMake;
string sModel;
string sColor;
string sPlate;
int iMinsParked;
public:
ParkedCar();
string getMake() const
{ return sMake; }
void setMake(string temp)
{ sMake = temp; }
string getModel() const
{ return sModel; }
void setModel(string temp)
{ sModel = temp; }
string getColor() const
{ return sColor; }
void setColor(string temp)
{ sColor = temp; }
string getPlate() const
{ return sPlate; }
void setPlate(string temp)
{ sPlate = temp; }
int getMins() const
{ return iMinsParked; }
};
ParkedCar::ParkedCar()
{
srand(time(NULL));
iMinsParked = (rand() % 10000);
}
class ParkingMeter
{
int iMinsPurch;
public:
void setMins(int temp)
{ iMinsPurch = temp; }
int getMins() const
{ return iMinsPurch; }
}
class Ticket : public ParkedCar
{
public:
string getName()
{ return sName; }
int getBadge()
{ return iBadge; }
};
class Officer
{
string sName;
int iBadge;
public:
friend string Ticket::getName();
//{ return sName; }
friend int Ticket::getBadge();
//{ return iBadge; }
};
int main()
{
ParkedCar Park;
cout << endl << endl;
cout << Park.getMins();
cout << endl << endl;
return 0;
}
Where I'm confused is mostly on the Ticket and Officer classes. The assignment clearly wants Ticket to have it's own information from all the other classes, but I'm not sure how to pass that information along. I've tried making it a child class of ParkedCar, but I just get a multiple definitions error. And I can't get the friend functions to work. I've tried them both ways and if I make them within Ticket, it tells me Officer isn't defined. And I'm really confused on how I'm supposed to write code for Officer generating an instance of Ticket when nothing has actually been initialized yet.
So:
How do I get all the information into the Ticket class?
How would I get Officer to generate an instance of Ticket?
Please keep in mind this is a STUDENT assignment, not something professional. I just want to do what the assignment says. I'm not interested in ways "around" the problem, because that's not what the prof wants.
Thanks in advance for your time. :D
Firstly: learn to use constructors. All this stuff you're setting...it is integral to the identity of a car, or a cop, etc. It should have been provided when the object was built. C++ isn't Java; quit treating classes like Java beans. :P
Secondly, a Ticket is not a ParkedCar. It associates with a car, but is not one itself. Consider instead:
class Ticket {
ParkedCar violator;
Officer issuer;
public:
Ticket(const Officer &cop, const ParkedCar &car) :
violator(car), issuer(cop) {
}
ParkedCar getCar() { return violator; }
Officer getOfficer() { return issuer; }
// Note, no mutators here!
// The biggest reason you had to have mutators, is that your construction
// was incomplete.
// The info associated with a Ticket should not be modified once the ticket
// is written. And since the constructor has all the info needed, there's no
// need to provide a way to modify them.
};
So an Officer doesn't need to know about the potentially-intricate details of a car, or exactly what info a Ticket needs. He can just hand himself and the car over to the constructor, and trust that it will extract whatever info it needs. (In this case, we just store copies of both items.)
class Officer {
std::string name;
int badge_number;
public:
Officer(const std::string& name, int badge) : name(name), badge_number(badge) { }
public std::string getName() { return name; }
public int getBadgeNumber() { return badge_number; }
Ticket writeTicketFor(const ParkedCar &violator) {
return Ticket(*this, violator);
}
};