C++ Using a class from a header within a class - c++

Question

I'm having a bit of trouble with classes used within classes, from header files.
I have a class time in time.h:
#ifndef TIME_H
#define TIME_H
#include <iostream>
using namespace std;
class Time
{
private:
int hour, minute, second;
public:
Time();
~Time();
Time(int h, int m, int s);
int getHour();
int getMinute();
int getSecond();
void setHour(int hour);
void setMinute(int minute);
void setSecond(int second);
Time getTimeFromUser(Time b);
bool validTime(Time a);
void print24Hour(Time a);
void print12Hour(Time b);
};
#endif
Schedule.h
#ifndef SCHEDULE_H
#define SCHEDULE_H
#include <iostream>
#include "time.h"
using namespace std;
class Class
{
private:
string name;
int credits;
bool majorRequirement;
double avgGrade;
string days;
Time startTime;
Time endTime;
public:
Class();
~Class();
Class(string namae, int cred, bool majorReq, double avg, string day);
//Mutate
void setName(string h);
void setCredits(int c);
void setMajorRequirement(bool set);
void setAvgGrade(double g);
void setDays(string d);
void getStartTimeFromUser(Time b);
void getEndTimeFromUser(Time e);
// Access
string getName();
int getCredits();
bool getMajorRequirement();
double getAvgGrade();
string getDays();
Time& getStartTime();
Time& getEndTime();
};
#endif
Schedule.cpp:
Class::Class()
{
string name = "";
int credits = 0;
bool majorRequirement = false;
double avgGrade = 0.0;
string days = "";
}
Time::Time()
{
int hour = 0;
int minute = 0;
int second = 0;
}
Class::Class(string namae, int cred, bool majorReq, double avg, string day)
{
name = namae;
credits = cred;
majorRequirement = majorReq;
avgGrade = avg;
days = day;
}
Time::Time(int h, int m, int s)
{
second = s;
minute = m;
hour = h;
}
Time getTimeFromUser(Time b)
{
string time = "";
string hourS, minuteS, secondS = new string();
getline(cin,time);
hourS = time.substr(0,2);
minuteS = time.substr(3,2);
secondS = time.substr(6,2);
b.hour = atoi(hourS.c_str());
b.minute = atoi(minuteS.c_str());
b.second = atoi(secondS.c_str());
return b;
}
void getStartTimeFromUser(Time b)
{
startTime = getTimeFromUser(b);
}
void getEndTimeFromUser(Time e)
{
endTime = getTimeFromUser(e);
}
Other Mutators and Accessors here.
Main is long. Here is the severely condensed version:
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <iomanip>
#include "time.h"
#include "schedule.h"
using namespace std;
int main()
{
// Expecting that variables are properly declared
Class * klass = new Class[classcount];
cout << "Enter the start time for the class (format is HH:MM:SS): ";
klass[i].getStartTimeFromUser(classB);
cout << "Enter the end time for the class (format is HH:MM:SS): ";
klass[i].getEndTimeFromUser(classE);
for(int i = 0; i < classcount; i++)
{
// Data collected via getline and changed through mutators/accessors
// Problems arise when working with Time
klass[i].getStartTime().print24hour();
}
}
I get quite a few "hour, second, minute, etc." are private errors, I'm guessing I'm doing something simple in a rather wrong way. Please help.
I get a lot of this:
time.h:10:7: error: ‘int Time::hour’ is private
schedule.cpp:146:4: error: within this context
time.h:10:13: error: ‘int Time::minute’ is private
schedule.cpp:147:4: error: within this context
time.h:10:21: error: ‘int Time::second’ is private
schedule.cpp:148:4: error: within this context
schedule.cpp: In function ‘void getStartTimeFromUser(Time)’:
schedule.cpp:155:16: error: ‘setStartTime’ was not declared in this scope
schedule.cpp: In function ‘void getEndTimeFromUser(Time)’:
schedule.cpp:160:2: error: ‘endTime’ was not declared in this scope
time.h: In function ‘bool validTime(Time)’:

Answer 1

There are several errors in your code:
I assume class in your main() function represents an array of
Class; but this is illegal, since class is a C++ keyword.
You are trying to access a private member of a Class object
(class[i].startTime). This is illegal again. You would need a
public accessor to that data member:
You are calling a function that does not exist (print24()). If you
intended to call print24hour(), this function takes no parameters.
Putting it all together, you need to do three things:
Add an accessor for startTime in Class:
class Class
{
//...
public:
Time GetStartTime() {return startTime;}
};
Use a legal name for your array and use std::vector or std::array:
std::vector<Class> classArray;
// OR:
std::array<Class, SIZE> classArray;
Call the right methods correctly:
classArray[i].GetStartTime().print24hour();

Answer 2

I you want to access class[i].startTime.print24(getStartTime()) from main you need to make startTimepublic.
If this is good style is a different question.

Answer 3

You are trying to access the private members of a class using the object directly.
Please read about public and private access specifiers here.

Answer 4

class Class
{
private:
Time startTime;
public:
const Time & getStartTime(){
return startTime;
}
};
int main()
{
Class c;
c.getStartTime().print24Hour();
}
You want either that, or make startTime public.
Note the const; if you don't want the returned reference to be const, then make startTime public right now. You may think that making it private improves encapsulation; and yes, it does, as long as you don't provide read-write access to the variable, which happens if you don't mark the member function return type const.
If your printing function isn't marked const, then your const-correctness doesn't exist. If using const reference as return type here, then you have some things to fix.
Related reading: Pseudo-Classes and Quasi-Classes.