Member variable in scope of one member function but not the other - c++

I'm seriously confused why this is happening. I get an error 'enzyme_acronyms_ was not declared in this scope'. It points to my writeAcronym function but not getAcronym, and both use enzyme_acronyms_. What can possibly cause this?
SequenceMap.h
#ifndef SequenceMap_h
#define SequenceMap_h
#include <iostream>
#include <string>
#include <vector>
using namespace std;
class SequenceMap
{
private:
string recognition_sequence_;
vector<string> enzyme_acronyms_;
public:
string getAcronym();
void writeAcronym(string an_enz_acro);
}
SequenceMap.cpp
#include "SequenceMap.h"
string SequenceMap::getAcronym()
{
return enzyme_acronyms_[0]; //works fine
}
void writeAcronym(string an_enz_acro)
{
enzyme_acronyms_.push_back(an_enz_acro); //enzyme_acronyms_ not declared in this scope
}

You've missed the SequenceMap:: qualification on the second function definition:
void SequenceMap::writeAcronym(string an_enz_acro)

It must be declared like this:
void SequenceMap::writeAcronym(string an_enz_acro)
{
enzyme_acronyms_.push_back(an_enz_acro);
}
You forgot the class scope SequenceMap::.

Related

C++ - error: class has not been declared/out of scope

So I have two classes - Dvd and DvdGroup. DvdGroup basically manages an array of dvds and provide manipulative member functions for that class. The problem is whenever I try to compile DvdGroup.cc using the command 'g++ -c Dvd.Group.cc', I get a bunch of errors all related to not having 'Dvd' declared and I'm not sure why.
Here are some errors below:
DvdGroup.h:14:12: error: ‘Dvd’ has not been declared void add(Dvd*);
DvdGroup.h:18:3: error: ‘Dvd’ does not name a type Dvd* dvdCollection[MAX_DVDS];
DvdGroup.cc: In copy constructor ‘DvdGroup::DvdGroup(DvdGroup&)’:
DvdGroup.cc:15:6: error: ‘Dvd’ was not declared in this scope for(Dvd d: dvds){
I feel like I'm missing something and they could all be fixed by one solution because they all involve having the Dvd class undeclared but I can't seem to figure out what. I was wondering if anyone could tell me what I'm doing wrong? I would really appreciate any help with fixing this.
DvdGroup.cc:
#include <iostream>
using namespace std;
#include "DvdGroup.h"
DvdGroup::DvdGroup(int n){
numDvds = n;
}
DvdGroup::DvdGroup(DvdGroup& dvds){
numDvds = dvds.numDvds;
for(Dvd d: dvds){
Dvd newDvd = Dvd;
}
}
DvdGroup::~DvdGroup(){
//code
}
void DvdGroup::add(Dvd* d){
//code
}
DvdGroup.h:
#ifndef DVDGROUP_H
#define DVDGROUP_H
#define MAX_DVDS 15
#include <string>
using namespace std;
class DvdGroup
{
public:
DvdGroup(int);
DvdGroup(DvdGroup&);
~DvdGroup();
void add(Dvd*);
private:
Dvd* dvdCollection[MAX_DVDS];
int numDvds;
};
#endif
Don't know if the Dvd header file is needed, but here:
Dvd.h:
#ifndef DVD_H
#define DVD_H
#define MAX_DVDS 15
#include <string>
class Dvd{
public:
Dvd(string, int);
void set(string, int);
Dvd(Dvd&);
int getYear();
~Dvd();
void print();
private:
string title;
int year;
};
#endif
What you need to do is to provide Dvd class definition for DvdGroup class. It is needed to know what type of symbol is this. Solution for your problem should be addition of:
#include "Dvd.h"
line to DvdGroup.h file.

C++ - Friend function unable to be called in main?

Im having trouble with a multi-file setup. Im working in visual studio, and, for whatever reason, my friend function in my class is not being defined in main. Any help would be appreciated, thanks.
BullCow.h:
#pragma once
#include <iostream>
#include <cstdlib>
#include <stdlib.h>
#include <time.h>
class BullCow {
public:
BullCow();
friend int getWins();
static int Wins;
private:
int Attempts;
};
BullCow.cpp:
#include "stdafx.h"
#include "BullCow.h"
int BullCow::Wins = 0;
int getWins() {
return Wins;
}
BullCowMain.cpp:
#include "stdafx.h"
#include "BullCow.h"
int main()
{
srand(time(NULL));
std::cout << getWins();
return 0;
}
Note: It's an incomplete program, so some code (srand) is not used yet. I just included everything to better help figure out what's wrong.
getWins() needs at least a declaration in the .h file.
Since it's a friend, getWins() is not a member of the class, so it must be declared either directly in BullCowMain.cpp or in some file BullCowMain.cpp includes.
Add this somewhere outside of the class in your header:
int getWins();
Also, inside getwins, the return should be:
return BullCow::Wins;
Thanks #user4581301!

Need help understanding object not declared in scope

I wrote down an example code to try to replicate the error I am getting in a school project about the scope of an object:
In file: classTest.cpp
#include "headerone.h"
#include "headertwo.h"
#include <iostream>
using namespace std;
int main() {
ClassOne* pntrObj1 = new ClassOne;
ClassTwo* pntrObj2 = new ClassTwo;
pntrObj1->testClassOne();
return 0;
}
In file: headerone.h
#ifndef HEADERONE_H
#define HEADERONE_H
#include "headertwo.h"
#include <iostream>
using namespace std;
class ClassOne {
public:
void testClassOne() {
cout << "One Worked\n";
pntrObj2->testClassTwo();
}
};
#endif
In file: headertwo.h
#ifndef HEADERTWO_H
#define HEADERTWO_H
#include <iostream>
using namespace std;
class ClassTwo {
public:
void testClassTwo() {
cout << "Two Worked";
}
};
#endif
To be clear, the error is: pntrObj2 was not declared in this scope. The error comes from the file headerone.h
If I had to guess, I need to somehow pass the reference but I am not sure where to start for that. Any help is appreciated.
The variable pntrObj2 is only visible inside the scope in which it was declared, in this case your function main(). In other words, only code inside the curly braces of main() would be able to use the name pntrObj2 to reference that variable. However you can pass that value to other pieces of code by making it the argument of a function call.
So maybe what you want to do is add an argument to the testClassOne() method, so you can pass in the value of pntrObj2. So pntrObj1->testClassOne(); would become pntrObj1->testClassOne(pntrObj2);, and where you define testClassOne you can add a corresponding parameter. I'll let you figure this out so as to not completely do your homework for you :)
Here you include your file a lot of time and in testClassOne function, you do not declare pntrObj2
use
void testClassOne() {
cout << "One Worked\n";
ClassTwo* pntrObj2 = new ClassTwo()
pntrObj2->testClassTwo();
}
insteed of
void testClassOne() {
cout << "One Worked\n";
pntrObj2->testClassTwo();
}

Data "member not declared in this scope"

I'm trying to create a vector which will store objects. I have added to the header file of the class as a private data member.
I am trying to initialize this vector as being empty (so that I can add objects to it later on in the program) but when I compile this program to test, this error is returned:
...error: '_bookingVector' was not declared in this scope|
I think the problem is with my initialization list on my default constructor(_bookingVector is obviously the vector):
Schedule::Schedule() : _bookingVector()
{ }
Is my syntax wrong? Or are vectors initialized differently?
Here is my code:
Schedule.h
#ifndef SCHEDULE_H
#define SCHEDULE_H
#include "Booking.h"
#include <vector>
using namespace std;
class Schedule
{
public:
Schedule();
void AddBooking(int bday, int btime, int btrainer, int bid);
void RemoveBooking(int bday, int btime);
void DisplaySchedule();
void DisplayAvailableTimeSlots();
//For Testing
void DisplayDebug();
private:
vector<Booking> _bookingVector;
};
#endif // SCHEDULE_H
Schedule.cpp
#include "Schedule.h"
#include "Booking.h"
#include <vector>
#include <iostream>
Schedule::Schedule() : _bookingVector()
{ }
void AddBooking(int bday, int btime, int btrainer, int bid){
Booking bookingObject(bday, btime, btrainer, bid);
_bookingVector.push_back(bookingObject);
}
void DisplayDebug(){
for(int i = 0; i < _bookingVector.size(); ++i){
cout << _bookingVecotr[i] << endl;
}
}
I'm very eager to learn what I'm doing wrong and fix it.
The issue is not with the constructor, which looks fine if unnecessary1. The issue is that you have defined AddBooking and DisplayDebug as non-member functions, but these should be members in order to access other members of the class.
Modify the definitions to be in the scope of the Schedule class thus:
void Schedule::AddBooking(int bday, int btime, int btrainer, int bid) { ...
^^^^^^^^^^
void Schedule::DisplayDebug(){ ...
^^^^^^^^^^
Also, don't say using namespace std in a header file (I'd go further and say don't say it anywhere but there isn't universal agreement on that.)
1 Your default constructor does not do anything that the compiler-generated one wouldn't do. You can safely remove it.

Copy constructor error c2039

hy guys! I have a code that gives me headaches. I would like some help please. This is my .h file.
#include <iostream>
#include <string>
using namespace std;
namespace UI{
class Comanda
{
private:
const string _nume;
public:
Comanda();
Comanda(const string &nume);
virtual ~Comanda();
const string& Nume() const;
virtual void AsteaptaEnter();
virtual void Execute();
};
};
And the .cpp:
#include <iostream>
#include <string>
#include "Comanda.h"
#include "Exceptii.h"
using namespace std;
using namespace UI;
Comanda::Comanda()
{
cout << "Comanda()" << endl;
}
Comanda::Comanda(const string &nume)
{
_nume = nume._nume;
}
The compiler shows me this error:
error C2039: '_nume' : is not a member of 'std::basic_string<_Elem,_Traits,_Ax>'
What should i do? Thanks in advance!
You must initialize the constant members in the initializer list of ctor, and also nume._nume is not valid.
Comanda::Comanda(const string &nume) : _nume(nume) {}
^^^^^^^^^^^^^
You probably meant
Comanda::Comanda(const string &nume)
{
_nume = nume;
}
It's not a copy constructor by the way.
_nume = nume._nume; this is wrong
it should be _nume = nume;
And as correctly pointed out by #Cornstalks you cannot achieve above assignments in any case as _nume is const.