Getting around using global variables

[kcschultz]

I am working on an assignment where the program calculates shipping costs based on data read in from a text file. I had it running with global variables but have been told by my instructor to not use global variables. Moving the variables, I have run into massive issues with scope and now it doesn't total at all.

Any suggestions on what I am not seeing would be great.

#include <iostream> 
#include <iomanip> 
#include <cmath> 
#include <fstream> 
#include "myheader.h"

using namespace std;  

  
void header(int lab_number, char lab_part)
{ 
	cout << "Kevin Schultz\n"; 
	cout << "Lab" << lab_number << lab_part << endl << endl; 
} 
  


int main () 
{ 
	double calculate(double length, double width, double height);
	double volume;
	double chargeAmount;
	double charge(ifstream & inFile, ofstream & prt);
	double length, width, height, weight, total = 0, shipping_cost, volume;

	ifstream inFile; 
	ofstream prt("lab7new_out.txt"); 
  
	header(7, 'A'); 
	prt << "        S & S Global Services\n";
	prt << "    Shipping Cost Analysis Report\n\n"; 
	prt << "Length Width Height Weight Shipping\n"; 
	prt << "                             Cost\n\n"; 
  
	inFile.open("c:\\lab7\\pkg.txt"); 
		if (!inFile) 
		cout << "Error opening the file\n"; 
  
	inFile >> length; 
	inFile >> width; 
	inFile >> height; 
	inFile >> weight; 
	  
	volume = calculate(length, width, height);
	chargeAmount = charge(inFile, prt, shipping_cost, volume, length, weight, width, height, total); //Getting the error here telling me that there are too many arguments in function. I have squiggly lines under shipping_cost?
  
	prt << "------------------------------------" << endl;
	prt << "\nTotal cost: $" << total; 
	
	system("pause"); 
	return 0;
   
} 

double calculate(double length, double width, double height)
		{ 
			double volume; 
			volume = length * width * height; 
			return volume; 
		} 

double charge(ifstream & inFile, ofstream & prt, double shipping_cost, double volume, double length, double weight, double width, double height, double total) 
		{
			const double basic_charge = 12;
			const double Vsurcharge = 5;
			const double Dsurcharge = 4;
			const double Wsurcharge = 2;
			double netWeight = 0;
			 
			while (!inFile.eof())  
			{ 
				shipping_cost = basic_charge; 
		 
				if (volume > 7)  
					shipping_cost += Vsurcharge; 
				if (length > 3 || width > 3 || height > 3) 
					shipping_cost += Dsurcharge; 
				if (weight > 50) 
				{
					netWeight = weight - 50;
					shipping_cost += netWeight * Wsurcharge; 
				}
				total += shipping_cost; 
				prt << setw(4) << right << setprecision(1) << length << setw(6) << right << setprecision(1) << width << setw(6) << right << setprecision(1) << height << setw(8) << right; 
				prt << weight << setw(5) << right << setprecision(2) << fixed << "$" << shipping_cost << endl; 
		  
				inFile >> length; 
				inFile >> width; 
				inFile >> height; 
				inFile >> weight; 
			}
			        return total;
		}

[vlad from moscow]

What do these definitions

double length, width, height, weight;
...
double volume = 0, shipping_cost;



do after function main()?

They are global as before only are not visible in main().:)

[ne555]

Please indent your code.
If you intend to avoid global variables, then avoid them. (remove their declaration)

[keskiverto]

Pass as reference parameters into functions, or

Define class types that hold data and have methods that update that data.

[kcschultz]

Changed the code, now the only error is too many arguments in function. I have shown it above.

[keskiverto]

Do not declare functions inside main().

Your function declaration does not match your function definition.

[vlad from moscow]

You declared the function as having two parameters

double charge(ifstream & inFile, ofstream & prt);

but defined it as having nine parameters.

double charge(ifstream & inFile, ofstream & prt, double shipping_cost, double volume, double length, double weight, double width, double height, double total)