Help with loop

The while loop does an extra iteration, and I don't know why. E.g. if there are only 2 lines in the file it is reading, it prints out the last price and quantity twice, and adds their product to sub. I think it prints out whitespace before that.

fin is an ifstream object. If I change the while condition to (!EOF), the file is not read at all.

I suspect that it has something to do with getline (fin, prodDesc), but prodDesc is a string that may contain spaces, so I don't know how else to read it in.

Any suggestions? My head is swimming.

-->Mariana

Code:

//this is part of a program that reads from a file
// and outputs a billing invoice

void processOrder(float&sub)
	
	{
	
	sub=0;
	
	do
	{
		fin>>code>>price>>quantity;
		getline (fin, prodDesc);
		total = price * quantity;
		cout<<fixed<<showpoint<<setprecision(2)
			<<setw(20)<<left<<code
			<<setw(20)<<left<<prodDesc
			<<setw(15)<<price
			<<setw(15)<<quantity
			<<setw(15)<<total;
		sub += total;
	}while(fin);

	cout<<setw(30)
		<<"Total order: $"
		<<setprecision(2)
		<<setw(15)
		<<fixed<<showpoint
		<<sub<<endl;
	
	}

A variation of the eof() problem discussed in the FAQ

Try

Code:

while ( fin>>code>>price>>quantity ) {
	getline (fin, prodDesc);
	total = price * quantity;
	cout<<fixed<<showpoint<<setprecision(2)
		<<setw(20)<<left<<code
		<<setw(20)<<left<<prodDesc
		<<setw(15)<<price
		<<setw(15)<<quantity
		<<setw(15)<<total;
	sub += total;
}

Thank you!

I actually asked a friend for help, and we ended up using the return value of getline() to break it up.

Code:

//Reads from file, calculates subtotal
void processOrder(float&sub)
	
	{
	
	sub=0;
	
	do
	{
		fin>>code>>price>>quantity;
		if (getline (fin, prodDesc) != 0)
		{
		total = price * quantity;
		cout<<fixed<<showpoint<<setprecision(2)
			<<setw(10)<<left<<code
			<<setw(20)<<left<<prodDesc
			<<setw(10)<<right<<price
			<<setw(15)<<quantity
			<<setw(15)<<total<<endl;
		sub += total;
		}
	}while(fin);

	cout<<setw(55)
		<<"Total order: $"
		<<setprecision(2)
		<<setw(15)
		<<fixed<<showpoint
		<<sub<<endl;
	
	}