creating an array with a struct

[Octoballa]

So Im trying to create an array with a size equal to the course variable of studenta. What am I doing wrong?

#include <iostream>
#include <string>
using namespace std;

struct Student {
	string firstName;
	string lastName;
	string aNumber;
	int courses;
	double gpa;
};

struct Course {
	int courseNumber;
	string courseName;
	int creditHours;
	char grade;
};

Student readStudent();
void readCourseArray(Student);

int main () {
	Student studenta;
	studenta = readStudent();
	readCourseArray(studenta);

		cout << studenta.firstName << endl;

system ("pause");
return 0;
}

Student  readStudent() {
	Student student1;

	cout << "What is your first name? ";
	cin >> student1.firstName;
	cout << "What is your last name? ";
	cin >> student1.lastName;
	cout << "What is your A number? ";
	cin >> student1.aNumber;
	cout << "How many classes are you taking? ";
	cin >> student1.courses;

	return student1;
}

void readCourseArray(Student studenta) {
	Course courseArray[studenta.courses];
}

[Dy7SLyTq]

the ugly way (in my opinion) is you have to do this:
Course courseArray = new Course[sizeof(studenta)]

of course it would be better to use std::vector<Course> courseArray (sizeof(studenta));

edit:
Course has to be a pointer

[Octoballa]

My instructor wouldn't allow the second option, because he hasnt covered it yet. But the first wasnt working.

[Dy7SLyTq]

im not actually sure i did it right hold on

[AbstractionAnon]

If you're going to do this with arrays, you're going to need a constant to define the size of the array.

const int MAX_STUDENT = 100;

Then declare studenta as an array.

Student studenta[MAX_STUDENTS];

You're going to need to keep track of the number of students read into each entry:

studenta[num_students++] = readStudent();

Not sure what you want to do with the course array.

@DTScode - new Course[sizeof(studenta)]
That going to allocate a number of occurrances of Course based on the byte size of a single Student instance. Probably not what you intended.

[Octoballa]

@AbstracionAnon Ive done it that way before, but I have to use the courses member variable. I cant just use a counter.

This is the prompt for the readCourseArray function:
-Use  the  student’s  number  of  courses  to  set  up  an  array.
-Prompts  the  user  for  information  about  each  course  the  student  has  taken:  the course  name,  the  course  number,  the  credit  hours,  and  the  student’s  letter  grade.  

[Octoballa]

I am completely stumped.

[AbstractionAnon]

I'd change your Student struct as follows:

struct Student 
{  string firstName;
    string lastName;
    string aNumber;
    int num_courses;
    Courses * courses;
    double gpa;
};

Now change line 44 as follows:

    cin >> student1.num_courses;
    //  Allocate a dynamic array to hold the courses for this student
    student1.courses = new Course [num_courses];

Now you want to loop through the number of courses prompting the user for the information for each course for that student.

Of course, Course must be declared before Student.

[Smac89]

The code you have seems to be compiling fine on my computer. Only warning is that Course courseArray[studenta.courses]; is not being used. What error are you getting exactly?

g++ -Wall -W -o tempStu Stu.cc
Stu.cc: In function ‘void readCourseArray(Student)’:
Stu.cc:53:10: warning: unused variable ‘courseArray’ [-Wunused-variable]

[Octoballa]

@Smac89 its saying that studenta.courses that defines the array, as in courseArray[studenta.courses], needs to be a constant value.

[Smac89]

Ok then what you have to do is either compile with the option -std=c++11 or make the create a dynamic course object so:

Course *courseArray = new Course[studenta.courses];

[cire]

Ok then what you have to do is either compile with the option -std=c++11

That will have no effect whatsoever. It's not any more legal in C++11 than it is in any other version of the standard. You can use the -ansi flag when compiling to disable nonstandard extensions if you're using a gcc variant.