Using a Do While Loop to pull Data from a file and then run the data through a switch.

[katiestevers]

Guys I'm so confused on this I'm trying to read the following data from a .txt file.
(file data)
This file contains the hights, radius, and the calculation that will be preformed.
1.0 1.0 C
1.0 1.0 V
1.0 1.0 S
1.0 1.0 D
1010.0 250.0 C
12.3 3.25 V
123.0 43.0 S
12.3 3.25 K
1.12 2.13 C
999
(end of file data)

I want the data to be read in by using a do while loop and in the loop I want three switch statements with the options 'C' 'V' and 'D'. These letter correspond with the type of calculation I want to do with the data. Here is what I currently have.

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

using namespace std;


int main()
{
	cout << " Kaitlin Stevers " << endl;
	cout << " February 12, 2017 " << endl;
	cout << " Program 4 " << endl;
	cout << " Geometries " << endl << endl;
	cout << " Height \tRadius \t\tCalculation Type \t Calculated Value " << endl;
	cout << "---------------------------------------------------------------------------------- "<< endl;
	


	float h, r;
	char caltype;
	char filename[200] = "Program4Data.txt";
	string fileinfo;
	cout << setprecision(2) << fixed;
	do
	{
		ifstream infile;
		infile.open(filename);
		getline(infile, fileinfo);
		cout << fileinfo << endl;
		infile >> h >> r >> caltype;
		switch(caltype)
		{
			case 'C' :
			case 'c' : 
				caltype = 'C';
				float answerc;
				answerc = 0; //circumfrence formula here//
				cout << h << "\t\t" << r << "\t\t" << "Circumference" << "\t" << answerc << endl;
				break;
			case 'V' :
			case 'v' :
				caltype = 'V';
				float answerv;
				answerv = 0; //volume formula here//
				cout << h << "\t\t" << r << "\t\t" << "Volume" << "\t\t" << answerv << endl;
				break;
			case 'S' :
			case 's' :
				caltype = 'S';
				float answersa;
				answersa = 0; //surface area formula here//
				cout << h << "\t\t" << r << "\t\t" << "Surface Area" << "\t" << answersa << endl;
				break;
			default:
				cout << " The calculation can not be completed because the data is invalid for 'calculation type' in the file. " << endl;
				break;
		} 
	}
		while( h != 999);
}

The compiles and builds. When I run it I get the default statement over and over. What have I done wrong? Also, where should I put [code] return 0; [\code]? Lastly the 999 at the end of the data is supposed to force the loop to stop because the height equals 999 at that point.

[katiestevers]

I've changed the code a little. Now it says error: switch quantity not an integer.

I know it isn't... It is a string letter intentionally.... Does it HAVE to be a char? Is that right?

Here is my code now..

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

using namespace std;


int main()
{
	cout << " Kaitlin Stevers " << endl;
	cout << " February 12, 2017 " << endl;
	cout << " Program 4 " << endl;
	cout << " Geometries " << endl << endl;
	cout << " Height \tRadius \t\tCalculation Type \t Calculated Value " << endl;
	cout << "---------------------------------------------------------------------------------- "<< endl;
	


	float h, r;
	string type;
	char filename[200] = "Program4Data.txt";
	string fileinfo;
	cout << setprecision(2) << fixed;
	do
	{
		ifstream infile;
		infile.open(filename);
		getline(infile, fileinfo);
		cout << fileinfo << endl;
		infile >> h >> r >> type;
		switch(type)
		{
			case 'C' :
			case 'c' : 
				type = 'C';
				float answerc;
				answerc = 0; //circumfrence formula here//
				cout << h << "\t\t" << r << "\t\t" << "Circumference" << "\t" << answerc << endl;
				break;
			case 'V' :
			case 'v' :
				type = 'V';
				float answerv;
				answerv = 0; //volume formula here//
				cout << h << "\t\t" << r << "\t\t" << "Volume" << "\t\t" << answerv << endl;
				break;
			case 'S' :
			case 's' :
				type = 'S';
				float answersa;
				answersa = 0; //surface area formula here//
				cout << h << "\t\t" << r << "\t\t" << "Surface Area" << "\t" << answersa << endl;
				break;
		} 
	}
		while( h != 999);
}

[whitenite1]

@katiestevers

Try changing line 22 from a string, to a char. Also, you could remove lines 37, 44 and 51, since type already equals those values.

EDIT:
I moved lines 29 and 30 outside the for loop, and placed a infile.close(); after the while command.
Also placed the switch statement in an if statement, so that things get printed ONLY if h != 999.
I see you also don't have a case check for 'D' and 'K', yet.

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

using namespace std;


int main()
{
	cout << " Kaitlin Stevers " << endl;
	cout << " February 12, 2017 " << endl;
	cout << " Program 4 " << endl;
	cout << " Geometries " << endl << endl;
	cout << " Height \tRadius \t\tCalculation Type \t\t Calculated Value " << endl;
	cout << "---------------------------------------------------------------------------------- "<< endl;



	float h, r;
	char type;
	char filename[200] = "Program4Data.txt";
	string fileinfo;
	ifstream infile;
	infile.open(filename);
	cout << setprecision(2) << fixed;
	do
	{

		//getline(infile, fileinfo); // Not needed
		//cout << fileinfo << endl; // Not needed. Prints line BUT nothing done with it
		infile >> h >> r >> type;
		if(h !=999)
		{
			switch(type)
			{
			case 'C' :
			case 'c' : 
				float answerc;
				answerc = 0; //circumfrence formula here//
				cout << h << "\t\t" << r << "\t\t" << "Circumference" << "\t\t" << answerc << endl;
				break;
			case 'V' :
			case 'v' :
				float answerv;
				answerv = 0; //volume formula here//
				cout << h << "\t\t" << r << "\t\t" << "Volume" << "\t\t\t" << answerv << endl;
				break;
			case 'S' :
			case 's' :
				float answersa;
				answersa = 0; //surface area formula here//
				cout << h << "\t\t" << r << "\t\t" << "Surface Area" << "\t\t" << answersa << endl;
				break;
			} 
		}
	}while( h != 999);
	infile.close();
}

[katiestevers]

Thanks. I am going to make a default statement for those. Those are invalid types.


When I run my code I get an output of blank lines that never end. I dont understand. :(

[whitenite1]

@katiestevers

Paste your new code here, and I'll look it over.

[katiestevers]

I used the exact code you posted. I've been busy so I haven't looked to see what is going wrong. When I run it I get the first few lines and then it prints blank lines.

[Pattako]

Your program looks relatively simple, but multiple issues.

First thing :

getline(infile, fileinfo);
cout << fileinfo << endl;
infile >> h >> r >> caltype;

What is the purpose of getline?? Since you already read h and r and caltype what is the need to read a whole line for nothing?

while( h != 999);

The condition may not be met and your program loops forever.

[JLBorges]

> I want the data to be read in by using a do while loop and in the loop I want three switch statements

Consider using a canonical while loop instead of a do-while loop; it is simpler.

std::ifstream infile(filename) ;

double height ;
double radius ;
char calc_type ;

// ideally, something like std::abs( height - 999.0 ) < 1.e-6 instead of height != 999
while( infile >> height && height != 999 && infile >> radius >> calc_type )
{
   // do what ever with height, radius and calc_type
   // eg. switch( calc_type ) etc. 
}

[katiestevers]

This worked perfectly! Thanks guys!

// Kailin Stevers
// February 12, 2017
// Program 4
// Geometries

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

using namespace std;


int main()
{
	cout << " Kaitlin Stevers " << endl;
	cout << " February 12, 2017 " << endl;
	cout << " Program 4 " << endl;
	cout << " Geometries " << endl << endl;
	cout << " Height \tRadius \t\tCalculation Type \t\t Calculated Value " << endl;
	cout << "---------------------------------------------------------------------------------- "<< endl;

	float h, r;
	char type;
	float pi;
	pi = 3.14159265359;
	char filename[200] = "Program4KaitlinSteversEGR126.txt";
	string fileinfo;
	ifstream infile;
	infile.open(filename); //Opens the file
	infile >> fileinfo; //Reads the first line.
	getline(infile, fileinfo); //Gets the line to display next.
	cout << fileinfo << endl; //Displays the line read in. 
	cout << setprecision(2) << fixed; //Sets ALL numbers to only two decimal places.
	do //Tells the program to keep reading in data till it hits the 999.
	{
		infile >> h >> r >> type; //This reads in the height, radius, and calculation type.
		if(h !=999)
		{
			switch(type) //This switches based on the type of calculation listed. 
			{
			case 'C' : //This case is chosen when the 'type' is C. 
			case 'c' : 
				float answerc;
				answerc = ( 2 * r) * pi; //This is the equation to calculate Circumfrence. 
				cout << h << "\t\t" << r << "\t\t" << "Circumference" << "\t\t" << answerc << endl;
				break;
			case 'V' : //This case is chose when the 'type' is V.
			case 'v' : 
				float answerv;
				answerv = pi * ( r * r ) * h; //This is the equation to find the Volume. 
				cout << h << "\t\t" << r << "\t\t" << "Volume" << "\t\t\t" << answerv << endl;
				break;
			case 'S' : //This case is chosen when the 'type' is S.
			case 's' :
				float answersa;
				answersa = (2 * pi * r * h) + (2 * pi * (r * r)); //This is the equation to find the surface area.
				cout << h << "\t\t" << r << "\t\t" << "Surface Area" << "\t\t" << answersa << endl;
				break;
			default:
				cout << h << "\t\t" << r << "\t\t" << "Invalid Character." << "\t" << "N/A" << endl; //The program defaults to this when the 'type' does not match C, V, or S.
			} 
		}
	}while( h != 999); // This tells the program to keep going till it reads in the height of 999 that is listed at the end. 
	infile.close();
}