strings and failed passing

[bmccormack]

I'm trying to have classification return two strings but it is only giving me one. I know that i can return more than one at a time so i tried messing around with void and passing by ref but i had trouble, any advice?

#include <iostream>
#include <iomanip>
#include <fstream>
#include <string> 
using namespace std;
string validity(double, double, double);
string classification(double, double, double);
string classi(double, double, double);
string kind(double, double, double);



int main()
{
	double a,b,c;
	double x=0,y=0;
	ifstream infile;
	ofstream outfile;
	outfile.open("output.txt");
	infile.open("input.txt");

	outfile << "Angle 1    Angle 2    Angle3    Status       Type           Kind" << endl;
	while(!infile.eof())
	{
	infile >> a >> b >> c;
	string i = validity(a,b,c);
	string t = classification(a,b,c);
	string k = classification(a,b,c);											
	outfile << a << setw(15) << b << setw(10) << c <<setw(10) << i << setw(13) << t << setw(15) << k << endl;
	if(i=="Valid")
		x++;
	else
		y++;
	}
	
	outfile <<"Valid Triangles: " << x << "\n" <<"Inavlid Triangles: " << y << endl;

	infile.close();
	outfile.close();
	return 0;
}

//checks for valid triangles 
string validity(double a, double b, double c)
{
	string i;
	if (a<0 || b<0 || c<0 || a+b+c==180)
		i="Valid";
		
	else 
		i="Invalid";
	return i;
}

//classifys the triangle
string classification(double a, double b, double c)
{
	string t = classi(a,b,c);
	string k = kind(a,b,c);
	return t,k;
}

string classi(double a, double b, double c)
{
	string t;
	if(a==b && b==c && a==c)
		t="equalaterial";
	
	else if(a==b || b==c || a==c)
		t="isosceles";

	else
		t="scalene";

	return t;
}

string kind(double a, double b, double c)
{
	string k;
	if(a==90 || b==90 || c==90)
		k="right";
	else if(a>90 || b>90 || c>90)
		k="obtuse";
	else
		k="acute";

	return k;
}

[Hambone]

TMK you can only return one. You could however, concat a string using the + operator giving you the illusion of returning two strings.

[bmccormack]

it works but a little messy in the outfile

[BHX]

If you wanted your code to stay close to the same, you could use references. Otherwise it is just a matter of manipulation and formatting to get it to look right.

 
void classification(double a, double b, double c, string &t, string &k)
{
      t = classi(a, b, c);
      k = kind(a, b, c);
}

// function call in main
string t, k;
classification(a, b, c, t, k);

Your code with my change and output.txt:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88

#include <iostream> #include <iomanip> #include <fstream> #include <string> using namespace std; string validity(double, double, double); void classification(double, double, double, string &t, string& k); string classi(double, double, double); string kind(double, double, double); int main() { double a,b,c; double x=0,y=0; ifstream infile; ofstream outfile; outfile.open("output.txt"); infile.open("input.txt"); outfile << "Angle 1 Angle 2 Angle3 Status Type Kind" << endl; while(!infile.eof()) { infile >> a >> b >> c; string i = validity(a,b,c); string t, k; classification(a, b, c, t, k); outfile << a << setw(15) << b << setw(10) << c <<setw(10) << i << setw(13) << t << setw(15) << k << endl; if(i=="Valid") x++; else y++; } outfile <<"Valid Triangles: " << x << "\n" <<"Inavlid Triangles: " << y << endl; infile.close(); outfile.close(); return 0; } //checks for valid triangles string validity(double a, double b, double c) { string i; if (a<0 || b<0 || c<0 || a+b+c==180) i="Valid"; else i="Invalid"; return i; } //classifys the triangle void classification(double a, double b, double c, string &t, string &k) { t = classi(a,b,c); k = kind(a,b,c); } string classi(double a, double b, double c) { string t; if(a==b && b==c && a==c) t="equalaterial"; else if(a==b || b==c || a==c) t="isosceles"; else t="scalene"; return t; } string kind(double a, double b, double c) { string k; if(a==90 || b==90 || c==90) k="right"; else if(a>90 || b>90 || c>90) k="obtuse"; else k="acute"; return k; }

Angle 1 Angle 2 Angle3 Status Type Kind 2 24 2 Invalid isosceles acute 60 60 60 Valid equalaterial acute 30 30 30 Invalid equalaterial acute 30 30 30 Invalid equalaterial acute Valid Triangles: 1 Inavlid Triangles: 3

[bmccormack]

oh i was told it goes like this string& t, thanks!

[BHX]

Well it can go either way <type>& t or <type> &t and same with pointers, but I prefer the latter especially if you are the kind of person that does like I do and make two or three declarators per line like I did with string t, k;. A lot of beginners get told to do the former and end up with errors like this:

// only the first is a pointer and the second one is an int
// not what the programmer intended
int* ptrFirstPointer, ptrSecondPointer;

// now both are pointers, though with C++11 I should really do
// is set both to nullptr...let me do that below
int *ptrFirstPointer = nullptr, *ptrSecondPointer = nullptr;

Glad I could help.