return 0; problem

[dznguy]

this prgm convert F to C or C to F.

#include <iostream>
#include <iostream>
#include <iomanip>
using namespace std;
double calcFahrenheit();
double calcCelsius();
int main()
{
double choice,choice1,choice2;
	do 
	{
        cout << "1. Convert F to C" << endl;
        cout << "2. Convert C to F" << endl;
		cout << "What is your choice?" << endl;
        cin >> choice;
	}
	while (choice == 1 && choice == 2);
	{
		if (choice == 2)
		{
		choice1 = calcFahrenheit();
		cout << choice1 << endl;
		}
		if (choice == 1)
		{
		choice2 = calcCelsius();
		cout << choice2 << endl;
		}
	}
	if (choice != 1 && choice != 2)
	cout <<"Invalid Input"<< endl;
	{ 
		system("Pause");
		return 0;
	}
  system("Pause");
  return 0;
}
double calcCelsius()
{
double start_temp,end_temp,temp_incr;
		cout << "Starting Temperature: ";
		cin >> start_temp;
		cout << "Ending Temperature: ";
		cin >> end_temp;
		cout << "Increasement by: ";
		cin >> temp_incr;
		cout << "Fahrenheit    Celsius"
		"\n---------------------"<<endl;
		for (double F=start_temp, C=(5.0/9.0)*(F-32.0); F<=end_temp; F=F+temp_incr , C=(5.0/9.0)*(F-32.0)) 
			{
			cout.precision(2);
			cout <<setw(8) <<fixed<< F << setw(12) << C <<"\n";
			}
		return 0;	
}
double calcFahrenheit()
{
double start_temp,end_temp,temp_incr;
		cout << "Starting Temperature: ";
		cin >> start_temp;
		cout << "Ending Temperature: ";
		cin >> end_temp;
		cout << "Increasement by: ";
		cin >> temp_incr;
		cout << "Celsius    Fahrenheit"
		"\n---------------------"<<endl;
		for (double C=start_temp, F=(9.0/5.0)*(C)+32.0; C <=end_temp; C=C +temp_incr , F=(9.0/5.0)*(C)+32.0) 
			{
			cout.precision(2);
			cout <<setw(8) <<fixed<< C << setw(12) << F <<"\n";
			}
		return 0; 
}

but in the output, there is this strange 0.00 that show up
i.e.

Celsius    Fahrenheit
---------------------
   0.00       32.00
  15.00       59.00
  30.00       86.00
0.00

in line 55 and 73 i use return 0; which should end that call fuction. here is the thing i dont get. if the call function successfully end, then why 0.00 show up? could anyone offer me an explanation or a way to fix so that 0.00 wont show up? thx

[D80DSL3A]

Try eliminating lines 22 and 27.
I'm surprised that line 17 ever lets you into the while loop. Did you mean to use || instead of && ?
If it were written like this while ( (choice == 1) && (choice == 2) ); then surely the loop would never be entered.

[firedraco]

Bad indentation:

do 
	{
        cout << "1. Convert F to C" << endl;
        cout << "2. Convert C to F" << endl;
		cout << "What is your choice?" << endl;
        cin >> choice;
	} //this is a do while loop
	while (choice == 1 && choice == 2);
	{ //random scope entry 

[D80DSL3A]

I see that now, thanks.

[AlphaBravo]

1. Line 17, why not have; while (choice != 1 && choice != 2); this would then eliminate the need for lines 30-35. If you wanted to warn user re; input you could put
if (choice != 1 && choice != 2) {cout<<"Invalid input, try again!\n";}
before line 17, ie; before the } while (choice != 1 && choice !== 2);

2. Line 36, change system ("pause") to cin.ignore().get();
(A safer replacement!)

3. Line 18 and 29 not sure why curly braces here??

4. Youve got #include <iostream> twice at top of code??

5. The 0.00 is occurring because of the for loop line 50. Why is a for-loop
being used for this calculation?