Switch statement for letter grade

[jnick12]

I need help with the //Find letterGrade function. The program works perfect with the if/else statements that are commented out, but I want to convert it to a switch statement. I did it, but it keeps saying that the variable 'grade' is being used without being initialized...Please help.

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

using namespace std;

//Function prototypes
void inputdata(string&, string&, double&, double&, double&, double&);
double findTotal(double t1, double t2, double lab, double final);
char letterGrade(double);
void displayHeading();
void display(string, string, double, double, double, double, double, char);

//Global Parameters

ifstream dataIn("data.txt");
ofstream dataOut("outdata.txt");

//Main 
int main()
{	
	//Delcare array size to hold # of people
	const int SIZE = 5;

	//Local Parameters
	string first[SIZE], last[SIZE];
	double test1[SIZE], test2[SIZE], lab[SIZE], final[SIZE];
	double numAvg[SIZE];
	char finalGrade[SIZE];
	
	//Function Call
	displayHeading();
	for (int i=0; i<SIZE; i++)
	{

	//Function Call
	inputdata(first[i], last[i], test1[i], test2[i], lab[i], final[i]);
	
	//Function Call
	numAvg[i] = findTotal(test1[i], test2[i], lab[i], final[i]);

	//Function Call
	finalGrade[i] = letterGrade(numAvg[i]);

	//Function Call
	display(first[i], last[i], test1[i], test2[i], lab[i], final[i], numAvg[i], finalGrade[i]);
	}
	
	dataIn.close();
	dataOut.close();
	
	cout <<"\n";
	system ("pause");
	return 0;
}

//Function to receive data and store it in main
void inputdata(string& fname,string& lname, double& test1, double& test2, double& lab, double& final)
{	
	
	dataIn>>fname>>lname>>test1>>test2>>lab>>final;
	
}

//Function to find numerical average
double findTotal(double t1, double t2, double lab, double final)
{
	double total;

	t1*=.20;
	t2*=.20;
	lab*=.25;
	final*=.35;

	total = (t1+t2+lab+final);
	return total;
	
}
	
//Function to find letter grade
char letterGrade(double numAvg)
{
	char grade;
	
	
	switch (grade)
	{
	case(1): 
		if (numAvg < 60)
		grade = 'F';
		break;
	case(2): 
		if (numAvg < 70)
		grade = 'D';
		break;
	case(3):
		if (grade < 80)
		grade = 'C';
		break;
	case(4):
		if (grade < 90)
		grade = 'B';
		break;
	default: grade = 'A';
	}
	return grade;
}


//	if (numAvg < 60)
//		grade = 'F';
//	else if (numAvg < 70)
//		grade = 'D';
//	else if (numAvg < 80)
//		grade = 'C';
//	else if (numAvg < 90)
//		grade = 'B';
//	else 
//		grade = 'A';
//
	
//Function to display heading
void displayHeading()
{
	cout<<left;
	cout<<setw(15)<<"NAME"<<setw(8)<<"TEST1"<<setw(8)<<"TEST2"<<setw(8)<<"LAB"<<setw(8)<<"FINAL"<<setw(8)<<"TOTAL"<<"GRADE";
	cout<<endl;
	cout<<"-----------------------------------------------------------------"<<endl;

	dataOut<<left;
	dataOut<<setw(15)<<"NAME"<<setw(8)<<"TEST1"<<setw(8)<<"TEST2"<<setw(8)<<"LAB"<<setw(8)<<"FINAL"<<setw(8)<<"TOTAL"<<"GRADE";
	dataOut<<endl;
	dataOut<<"-----------------------------------------------------------------"<<endl;
	
	
}

//Function to display data
void display(string f, string l, double t1, double t2, double lab, double final, double numAvg, char finalGrade)
{
	string n;
	n = f +" "+l;
	cout<<left<<fixed<<showpoint<<setprecision(1);
	cout<<setw(15)<<n<<setw(8)<<t1<<setw(8)<<t2<<setw(8)<<lab<<setw(8)<<final<<setw(8)<<numAvg<<setw(8)<<finalGrade;
	cout<<endl;

	//Send data to outfile
	dataOut<<left<<fixed<<showpoint<<setprecision(1)<<endl;
	dataOut<<setw(15)<<n<<setw(8)<<t1<<setw(8)<<t2<<setw(8)<<lab<<setw(8)<<final<<setw(8)<<numAvg<<setw(8)<<finalGrade;
		
}

[Crutoy]

line 84 you declared it but its not initialized to anything so when you get to line 87 it throws the error. you should replace grade with numAvg in switch

[Ancient Dragon]

If statements are better than switch in this case because switch can not be used with ranges of values. For exxample you can not say case numAvg < 60

[Crutoy]

i guess i didn't think thru my comment because numAvg will not match any label.

[alaa sam]

ok what grade is supposed to store ?
tell us so that we can help
, as they said the if statement is much better in your case .

[jnick12]

grade is to supposed to store a char variable ex. A, B, C, D, F

[alaa sam]

even if you assigned some thing to grade it won't work as you want , cause it won't match any case , try this
1- add a new function that takes the mark in numbers as parameter and this function return 1 if the mark is less than 60 and so on
2- modify your letter grade function to have two parameters the extra one has the value returned from the function i mentioned earlier , and use it in the switch statement