Problem with accessing objects of vectors

[ree]

Unlike arrays I am having problems accessing objects placed in a vector

I have a vector of objects called Semesters

Each Semester has its own vector of Subjects.

I am having problems accssing attributes of the a subject given a
particular semester.

Can someone help me out with the syntax

[Dave]

"ree" <re*@hotmail.co om> wrote in message
news:Xn******** *************** ****@211.29.133 .50...

Unlike arrays I am having problems accessing objects placed in a vector

I have a vector of objects called Semesters

Each Semester has its own vector of Subjects.

I am having problems accssing attributes of the a subject given a
particular semester.

Can someone help me out with the syntax

It might help if you post some code, but here's a stab at it:

Semesters[i] gives you semester i
Semesters[i].Subjects gives you the subjects for semester i
Semesters[i].Subjects[j] gives you subject j for semester i
Semesters[i].Subjects[j].name( ) gives you the name of subject j for
semester i

(Assuming your subject class has a name() method)

HTH,
Dave

[ree]

I am actually passing one of the semesters to a particular function.
---
Semester * newSemester = new Semester(name, intYear, season,rSem);
semesters.push_ back(newSemeste r);

HtmlWriter HtmlSemesterPag e;
HtmlSemesterPag e.htmlSemesterP age(*newSemeste r);

---
In that function i am trying to read the courseId string from the first
subject in the semester.

void HtmlWriter::htm lSemesterPage(S emester theSemester)
{
std::string subjectId = theSemester.the Subjects[0].getCourseId();
but I keep getting this error...
error C2228: left of '.getCourseId' must have class/struct/union type


"Dave" <be***********@ yahoo.com> wrote in news:vqrblss9sl ahe0
@news.supernews .com:

"ree" <re*@hotmail.co om> wrote in message
news:Xn******** *************** ****@211.29.133 .50...

Unlike arrays I am having problems accessing objects placed in a vector
I have a vector of objects called Semesters

Each Semester has its own vector of Subjects.

I am having problems accssing attributes of the a subject given a
particular semester.

Can someone help me out with the syntax

It might help if you post some code, but here's a stab at it:

Semesters[i] gives you semester i
Semesters[i].Subjects gives you the subjects for semester i
Semesters[i].Subjects[j] gives you subject j for semester i
Semesters[i].Subjects[j].name( ) gives you the name of subject j for
semester i

(Assuming your subject class has a name() method)

HTH,
Dave

[Dave]

"ree" <re*@hotmail.co om> wrote in message
news:Xn******** *************** *****@211.29.13 3.50...

I am actually passing one of the semesters to a particular function.
---
Semester * newSemester = new Semester(name, intYear, season,rSem);
semesters.push_ back(newSemeste r);

HtmlWriter HtmlSemesterPag e;
HtmlSemesterPag e.htmlSemesterP age(*newSemeste r);

---
In that function i am trying to read the courseId string from the first
subject in the semester.

void HtmlWriter::htm lSemesterPage(S emester theSemester)
{
std::string subjectId = theSemester.the Subjects[0].getCourseId();
but I keep getting this error...
error C2228: left of '.getCourseId' must have class/struct/union type

Could you please show your class definitions for Semester and Subject?
Thanks!

[ree]

Semester.h
-------
#include <vector>
#include <iostream>
#include <fstream>
#include <string>

#include "Subject.h"
using namespace std;

class User;
class Subject;

class Semester
{
public:
Semester( std::string, int , std::string, int);
~Semester ();

std::string getsemesterName () const;

void loadSubjects();

void addSubject(std: :string, std::string);
vector <Subject *> theSubjects;

private:
std::string semesterName;
bool currentSemester ;
int year;
std::string season;
};
-------

Subject.h

#include <iostream>
#include <fstream>
#include <string>

#include "SubjectDat a.h"

class Semester;
class SubjectData;

class Subject
{
public:
Subject ();
Subject(std::st ring, std::string);

~Subject ();
std::string getSubjectName( ) const;
std::string getCourseId() const;

void setSubjectName( std::string name);
void setCourseId(std ::string id);

void downloadSubject Data();
void loadSubjectData ();

SubjectData theSubjectData[7];
private:
std::string subjectName;
int subjectNumber;
std::string courseId;
bool monitor;

};



"Dave" <be***********@ yahoo.com> wrote in news:vqreah8lln 8n31
@news.supernews .com:

"ree" <re*@hotmail.co om> wrote in message
news:Xn******** *************** *****@211.29.13 3.50...

I am actually passing one of the semesters to a particular function.
---
Semester * newSemester = new Semester(name, intYear, season,rSem);
semesters.push_ back(newSemeste r);

HtmlWriter HtmlSemesterPag e;
HtmlSemesterPag e.htmlSemesterP age(*newSemeste r);

---
In that function i am trying to read the courseId string from the first subject in the semester.

void HtmlWriter::htm lSemesterPage(S emester theSemester)
{
std::string subjectId = theSemester.the Subjects[0].getCourseId();
but I keep getting this error...
error C2228: left of '.getCourseId' must have class/struct/union

type
Could you please show your class definitions for Semester and Subject?
Thanks!

[Artie Gold]

ree wrote:

Semester.h
-------
#include <vector>
#include <iostream>
#include <fstream> #include <string>

#include "Subject.h"
using namespace std;

class User;
class Subject;

class Semester
{
public:
Semester( std::string, int , std::string, int);
~Semester ();

std::string getsemesterName () const;

void loadSubjects();

void addSubject(std: :string, std::string);
vector <Subject *> theSubjects;

private:
std::string semesterName;
bool currentSemester ;
int year;
std::string season;
};
-------

Subject.h

#include <iostream>
#include <fstream> #include <string>

#include "SubjectDat a.h"

class Semester;
class SubjectData;

class Subject
{
public:
Subject ();
Subject(std::st ring, std::string);

~Subject ();
std::string getSubjectName( ) const;
std::string getCourseId() const;

void setSubjectName( std::string name);
void setCourseId(std ::string id);

void downloadSubject Data();
void loadSubjectData ();

SubjectData theSubjectData[7];
private:
std::string subjectName;
int subjectNumber;
std::string courseId;
bool monitor;

};



"Dave" <be***********@ yahoo.com> wrote in news:vqreah8lln 8n31
@news.supernews .com:

"ree" <re*@hotmail.co om> wrote in message
news:Xn****** *************** *******@211.29. 133.50...

I am actually passing one of the semesters to a particular function.
---
Semester * newSemester = new Semester(name, intYear, season,rSem);
semesters.pu sh_back(newSeme ster);

HtmlWriter HtmlSemesterPag e;
HtmlSemester Page.htmlSemest erPage(*newSeme ster);

---
In that function i am trying to read the courseId string from the

first

subject in the semester.

void HtmlWriter::htm lSemesterPage(S emester theSemester)
{
std::strin g subjectId = theSemester.the Subjects[0].getCourseId();
Since theSemester.the Subjects[0] is of type std::vector<Sub ject *>,
the above line should be:

std::string subjectId = theSemester.the Subjects[0]->getCourseId( );


but I keep getting this error...
error C2228: left of '.getCourseId' must have class/struct/union

type

Could you please show your class definitions for Semester and Subject?

HTH,
--ag
--
Artie Gold -- Austin, Texas
Oh, for the good old days of regular old SPAM.

[Dave]

> >> void HtmlWriter::htm lSemesterPage(S emester theSemester)

{
std::string subjectId = theSemester.the Subjects[0].getCourseId();
but I keep getting this error...
error C2228: left of '.getCourseId' must have class/struct/union

type

Could you please show your class definitions for Semester and Subject?
Thanks!

theSemester.the Subjects[0] is a pointer. So, you need to use "->" rather
than "." after it. See below:

std::string subjectId = theSemester.the Subjects[0]->getCourseId( );

[ree]

Thanks boths of you guys it worked.

[ree]

Thanks boths of you guys it worked.

[Ron Natalie]

"ree" <re*@hotmail.co om> wrote in message news:Xn******** *************** *****@211.29.13 3.50...

vector <Subject *> theSubjects;

This is a vector of pointers.

Semester * newSemester = new Semester(name, intYear, season,rSem);
semesters.push_ back(newSemeste r);
Pushing a poitner, fine.
std::string subjectId = theSemester.the Subjects[0].getCourseId();

theSemebers.the Subjects[0] has type Subject*. You can't apply the . operator
to that. As the compiler told you, it needs to be a class type to do that.

You wanted to write:
std::string subjectId = theSemester.the Subjects[0]->getCourseID( );

As