Win32 Console Application won't run in VS2012 Pro - c++

Question

I am teaching myself C++ with Prata's C++ Primer Plus and am having an issue. I don't get any errors in VS2012 Pro and the program compiles successfully but gives me an unhandled exception (Unhandled exception at 0x76ED016E (ntdll.dll) in Prata 2.5.exe: 0x00000000: The operation completed successfully.) when I try to enter C or F as my initial option and I am not sure where I have gone wrong. The exercise only asked me to create a simple program that converted Fahrenheit to Celsius, but I thought that I would find something like this useful as I often use online sources to do this conversion. If I had my own program, I wouldn't have to worry and can expand it to a non CLI version and more conversion options (ie. yards to metres etc). Any help would be appreciated.
#include "stdafx.h"
#include <iostream>
// Function Prototypes
double convertToF(double);
double convertToC(double);
int main()
{
using namespace std;
char* convertChoice = "a"; // Initializing because the compiler complained. Used to choose between celsius and fahrenheit.
int choiceNumber; // Had issues using the char with switch so created this.
double tempNumber; // The actual temperature the user wishes to convert.
cout << "Do you wish to convert to [C]elcius or [F]ahrenheit?";
cin >> convertChoice;
// IF() compares convertChoice to see if the user selected C for Celsius or F for fahrenheit. Some error catching by using the ELSE. No converting char to lower though in case user enters letter in CAPS.
if (convertChoice == "c")
{
cout << "You chose Celsius. Please enter a temperature in Fahreinheit: " << endl;
cin >> tempNumber;
choiceNumber = 1;
}
else if (convertChoice == "f")
{
cout << "You chose Fahrenheit Please enter a temperature in Celsius: " << endl;
cin >> tempNumber;
choiceNumber = 2;
}
else
{
cout << "You did not choose a valid option." << endl;
}
// SWITCH() grabs the int (choiceNumber) from the IF(), goes through the function and outputs the result. Ugly way of doing it, but trying to make it work before I make it pretty.
switch (choiceNumber)
{
case 1:
double convertedFTemp;
convertedFTemp = convertToC(tempNumber);
cout << convertedFTemp << endl;
break;
case 2:
double convertedCTemp;
convertedCTemp = convertToF(tempNumber);
cout << convertedCTemp << endl;
break;
default:
cout << "You did not choose a valid option." << endl;
break;
}
// To make sure the window doesn't close before viewing the converted temp.
cin.get();
return 0;
}
// Function Definitions
double convertToF(double x)
{
double y;
y = 1.8 * x + 32.0;
return y;
}
double convertToC(double x)
{
double y;
y = x - 32 / 1.8;
return y;
}
I also don't know if I have everything right. ie. The formula in the functions as well as the order of the switch. Please don't correct that, I'll figure that out for myself once the damn thing compiles. :)

Answer 1

Please refer to the rule of thumb in the comments. You are using a char* without enough knowledge of the details to use it properly. Use std::string, it will do exactly what you need.
For future reference: With a char*
you need to allocate memory
you need to use strcmp to compare
you need to watch the length yourself
you need to deallocate the memory
That's a lot for starters. Use std::string.
string convertChoice = "a";
Don't forget to
#include <string>