Unresolved externals;

[dman951753]

These are the errors I am getting:
Error 3 error LNK2019: unresolved external symbol "public: __thiscall StudentTestScores::StudentTestScores(void)" (??0StudentTestScores@@QAE@XZ) referenced in function _main c:\Users\cohena2\documents\visual studio 2010\Projects\6\6\NewLab6 Main.obj

Error 4 error LNK1120: 1 unresolved externals c:\users\cohena2\documents\visual studio 2010\Projects\6\Debug\6.exe 1

This is my class declaration:

#ifndef STUDENTTESTSCORES_H
#define STUDENTTESTSCORES_H
#include <string>
#include <iostream>
#include <fstream>
using namespace std;

class StudentTestScores;
const double NA= 0;



class StudentTestScores
{
	private:
		string studentName;
		double *testScores;
		int numTestScores;
		char LetterGrade;
		void createTestScoresArray(int size)
		{
			numTestScores=size;
			testScores=new double[size];
			for (int i=0; i<size; i++)
			{	
				testScores[i]=NA;
			}
		}
    public:
		// class constructor
		StudentTestScores();
		StudentTestScores(string name, int numScores ) 
		{ 
			studentName=name;
			createTestScoresArray(numScores);
		}

		// class copy constructor
		StudentTestScores(const StudentTestScores &other) 
		{
			studentName = other.studentName;
			numTestScores = other.numTestScores;
			testScores = new double[numTestScores];
			for (int i = 0; i < numTestScores; i++)
			{
				testScores[i] = other.testScores[i];
			}
		}
		
		// class destructor
		~StudentTestScores()
		{	delete [] testScores;}
	
		// accessors & mutators 
		void setLetterGrade(char x)
		{ LetterGrade=x;}

		char getLetterGrade()
		{ return LetterGrade;}

		void setName(string x)
		{	studentName=x;}
	
		string getName() const
		{	return studentName;}
		
		void setTestScore(double score, int index)
		{	testScores[index] = score;}

		double getTestScore(int index)const
		{	return testScores[index];}

		void setNumTestScores(int x)
		{ numTestScores=x;}
	
		int getNumTestScores() const
		{	return numTestScores;}
				
		//Assignment operator overload
		void operator=(const StudentTestScores &other)
		{
			delete [] testScores;
			studentName = other.studentName;
			numTestScores =other.numTestScores;
			testScores = new double[numTestScores];
			for(int i = 0; i < numTestScores; i++)
			{
				testScores[i] = other.testScores[i];
			}

		}
		
		friend ostream& operator <<(ostream &, StudentTestScores &);
		friend istream& operator >>(istream &, StudentTestScores &);

		friend ifstream& operator >>(ifstream &, StudentTestScores &);
		
		//displayInfo prototype
		void displayInfo(StudentTestScores);

};

//Overload the Stream I/O operators. 
ostream& operator <<(ostream &os, StudentTestScores &x)
	{	
			os<< x.getName() << "\t" << x.getNumTestScores() << "\t" << x.getLetterGrade()<<"\t";

		
	for (int i = 0; i < x.getNumTestScores(); i++)
	{
			os<< x.getTestScore(i)<<", ";
	}
	cout<<".\n";
		return os;
	}

istream& operator >>(istream &is, StudentTestScores &object)
	{
		cin.get();
		cout<<"Enter student name : ";	
		
		getline(is,object.studentName);
		
	
		cout<<"Enter number of test scores : ";
		is>>object.numTestScores;
		
		object.testScores=new double[object.numTestScores];
				
		for(int i=0; i<object.numTestScores;i++)
		{
			
			cout<<"Enter score for test"<<(i+1)<<" : ";
			is>>object.testScores[i];
		
		}

		return is;
	}

ifstream& operator >>(ifstream &file, StudentTestScores &obj)
{
    int numTestScores=0;
	float sum=0;
	string Name;
	
	getline(file, Name, '\t');
	file>>numTestScores;
	
	StudentTestScores(Name, numTestScores);
	
	for(int i=0; i<obj.numTestScores;i++)
		{
			file>>obj.testScores[i];
			sum=sum+obj.testScores[i];		
		}

	if (sum>=90 && sum<=100)
		obj.setLetterGrade('A');
	else if (sum>=80 && sum<=89)
		obj.setLetterGrade('B');
	else if (sum>=70 && sum<=79)
		obj.setLetterGrade('C');
	else if (sum<=69&& sum>=0)
		obj.setLetterGrade('D');
	else
		obj.setLetterGrade('N');

	return file;

}



#endif 

This is my client code. The real error occurs on line 26.

#include "STUDENTTESTSCORES 5.h"
#include <string>
#include <iostream>
#include <fstream>
using namespace std;

void showContent(fstream&);

int main()
{	
	StudentTestScores *ptr;
	
	fstream file;
	int numOfStudents;
		
	file.open("C:\\Users\\cohena2\\Desktop\\tests.txt", ios::app || ios::in);
	
	if(!file)
	{ cout<<"file not found\n";}
	else if (file) 
	{cout<<"File found \n";}
			
	file>>numOfStudents;
	cout<<numOfStudents;

	ptr=new StudentTestScores[numOfStudents];
	
	for(int i=0; i<numOfStudents;i++)
	{
		file>>ptr[i];
	}

	//output 
	for( int i =0; i < numOfStudents; ++i)
	{ cout << ptr[i] << endl;}		
	
	//showContent(file);
	
	cin.get();cin.get();
	return 0;
}

void showContent(fstream &file)
{
	string line;

	while(getline(file,line))
	{
		cout<<line<<endl;
	}
	
}

Any help would be appreciated, let me know if you have any questions

[LB]

You're getting a linker error, which most likely means you defined a function 0 times or 2 or more times. All functions need to be defined exactly once.

In this particular case, your linker error is saying that you never defined your default constructor.

[dman951753]

I commented out the parameterised constructor and adjusted code for the overloaded operators accordingly.
I am still getting the same error.

Changed Code:

 public:
		// class constructor
		StudentTestScores();
		/*StudentTestScores(string name, int numScores ) 
		{ 
			studentName=name;
			createTestScoresArray(numScores);
		}*/
.....

ifstream& operator >>(ifstream &file, StudentTestScores &obj)
{
    int numTestScores=0;
	double sum=0;
	string Name;
	
	getline(file, Name, '\t');
	file>>numTestScores;
	
	//StudentTestScores(Name, numTestScores);
	
	obj.setName(Name);
	obj.setNumTestScores(numTestScores);
	obj.createTestScoresArray(numTestScores);

the rest of the code is the same.

I showed it to the teacher and several other students, no one knows what's going on. They are of no help to me, I need you guys' input please :) thx in advance.

[LB]

LB wrote:

your default constructor.

dman951753 wrote:

the parameterised constructor

[dman951753]

Thx for the help figuring it out, that part of the code now works correctly.