using switch to create an object

[djardim]

Here's the situation... I'm trying to make a 'gradebook' sorta program. I know the code isn't even close to being optimized nor programmed in the best way. The problem.. I can't seem to create an instance of CStudent in a switch statement. I want to use the switch statement to create a menu to give an option of adding a student, printing a student, etc... When I try to compile I get an error: "initialization of Student1 is skipped by case label"

#include <iostream>
using namespace std;

class CStudent //sizeof(CStudent) = 50 bytes
{
	public:
		CStudent()		{setAll();} //my constructor
		~CStudent(){;}
		char firstName[20];	//1x20 =20 bytes
		char lastName[20];	//1x20 =20 bytes
		unsigned short grades[5]; //2x5 = 10 bytes

		//public member methods
		void printAll(int x);


	private:
		void setAll();

};

void CStudent::setAll()
{


	cout << "------- Creating a new Student ---------" << endl;
	cout << "Enter First Name: ";
	cin >> this->firstName;
	cout << "Enter Last Name: ";
	cin >> this->lastName;

	//use loop to enter grades
	//starts with 0 and goes to 4 //total = 5 grades
	for(unsigned short gradeNum = 0; gradeNum < 5; gradeNum++)
	{
	cout << "Enter Grade #" << (gradeNum + 1) << ": ";
	cin >> this->grades[gradeNum];
	}
}

void CStudent::printAll(int x)
{
	cout << "\n---------- Printing Student Info ----------" << endl;
	cout << "Student Number " << (x+1) << endl;
	cout << "First Name:\t" << this->firstName << endl;
	cout << "Last Name:\t" << this->lastName << endl;

	//prints grades 0 to gradeNum
	for(unsigned short gradeNum = 0; gradeNum < 5; gradeNum++)
	{
	cout << "Grade #" << (gradeNum+1) << " grade:\t" << grades[gradeNum] << endl;
	}

}



int main()
{
	//Menu
	unsigned short option;
	cout << "Enter #: " << endl;
	cin >> option;

	//switch statement based on option
	switch(option)
	{
	case 1: //create an instance of a Student
		CStudent Student1;
		break;

	case 2: //print an instance of a Student
		Student1.printAll(0);
		break;

	case 3: //print sizeof
		cout << "Size of Student: " << sizeof(Student1) << endl;

	case 4: //exit
		return 0;
		break;

	default:
		cout << "\nError!" << endl;
		break;
	}


	return 0; //the switch should take care of exit
}

Thanks for the help

[Daved]

You need a way to store new students when you create them. A simple way would be to use a vector (or array). When the user chooses option one, you push a student back on to the vector (or set the data in a certain part of the array).

If you just want to test your code with a single student first, move that line of code outside the switch and call setAll when the user selects option 1.

[hk_mp5kpdw]

switch(option)
{
case 1: //create an instance of a Student
    CStudent Student1;
    break;

case 2: //print an instance of a Student
    Student1.printAll(0);
    break;

What happens if option is 2? You end up skipping the code that constructs your Student1 object and go right to using the object.. the very one that doesn't exist because you haven't constructed it yet. That's what the error is telling you.

[CodeMonkey]

int main()
{
	//Menu
	unsigned short option;
        CStudent* Student1 = NULL;

        while(true)
        {
	cout << "Enter #: " << endl;
	cin >> option;

	//switch statement based on option
	switch(option)
	{
	case 1: //create an instance of a Student
                if(Student1 != NULL) delete Student1;
                Student1 = new CStudent;
		break;

	case 2: //print an instance of a Student
                if(Student1 != NULL) Student1->printAll(0);
                else cout << "Need to initialize with '1'" << endl;
		break;

	case 3: //print sizeof
		if(Student1 != NULL) cout << "Size of Student: " << sizeof(*Student1) << endl;
               else cout << "Need to initialize with '1'" << endl;
               break;

	case 4: //exit
                if(Student1 != NULL) delete Student1;
                return 0;
		break;

	default:
		cout << "\nError!" << endl;
		break;
	}
        }//while loop

        if(Student1 != NULL) delete Student1;
	return 0; 
}