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tbeck1982

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Promblem with switch structure in C++

I am having a promblem with a case statement. I am trying to pass an array of letters to this switch statement so that I can assign calues to it. Whenever I try to call the function that has the switch statement
it does nothing and theprogram ends. I would apperciate any advice that can be offered, Below is my code.
#include<iostream>
#include<iomanip>
#include<string>
using namespace std;


void returnRoman(char roman[]);      
void returnArabic(char roman[], int arabicNum);
void checkInput(char roman[]);

class romanType
{
      // 0 < num < 3999
public:
      void returnRoman(char roman[16]);                              //Returns a roman numeral
      void returnArabic(char roman[16], int arabicNum);      //Returns a arabic number
      void checkInput(char roman[16]);                              //Checks to see if the roman numeral is in the proper
                                                                                    //form

private:
      int arabicNum; //The variable that stores the arabic number


}; //class romanType

void main()
{
      int index      = 0;
      int arabicNum = 0;
      char roman[16];
      romanType romanNumeral;

      for(index = 0; index<16; index++)
            {
                  roman[index] = 0;
            }
      
      
      cout << "Please enter a roman numeral that you would like to convert." << endl;
      cout << "Make sure that the numerals are in uper-case only." << endl;
      cout << "Enter in the upper-case 'Q' when finished entering numerals." << endl;
      
index = -1;      

      while(roman[index] != 'Q')
            {
                  index++;
                  cin.get(roman[index]);
                  
            }      
      
      
      //romanNumeral.returnArabic(roman, arabicNum);
            romanNumeral.returnRoman(roman);
      
      

      return;
}//function main

void romanType::checkInput(char roman[])
{
      


      return;
}//function checkInput

void romanType::returnRoman(char roman[])
{
      int index = 0;
      
            for(index = 0; index<16; index++)
      {
            cout << roman[index];
      }

      return;
}//function returnRoman

void romanType::returnArabic(char roman[], int arabicNum)
{
      int index = 0;
      int value = 0;
      
      
while(roman[index] != 'Q')
{
      switch (roman[index])
      {
                          case 'M': case 'm':
                              value = 1000;
                                          break;
                  case 'D': case 'd':
                              value = 500;
                                          break;
                  case 'C': case 'c':
                              value = 100;
                                          break;
                  case 'L': case 'l':
                              value = 50;
                            break;
                  case 'X': case 'x':
                              value = 10;
                                          break;
                  case 'V': case 'v':
                              value = 5;
                                          break;
                  case 'I': case 'i':
                              value = 1;
                                          break;
                         
                        arabicNum = value + arabicNum;
                        index++;
      
      }//end of switch structure
}//end of while loop
      

cout << arabicNum << endl;
      return;
}//function returnArabic

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Infinity08
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A few more things :

1) main must return int :

        int main() {
            // ...

            return 0;
        }

2) These three function prototypes before the class definition shouldn't be there :

        void returnRoman(char roman[]);      
        void returnArabic(char roman[], int arabicNum);
        void checkInput(char roman[]);

    You can just remove them.

3) Taking a value outside of the array bounds is dangerous. For the first iteration of the following loop, you're taking the character just before the array :

        index = -1;      

        while(roman[index] != 'Q')

    Change the loop like this instead :

        index = -1;

        do {
              index++;
              cin.get(roman[index]);
        } while(roman[index] != 'Q');

3) For the arabicNum() method, you don't need to pass arabicNum like you do :

        void romanType::returnArabic(char roman[], int arabicNum)

    Use this method instead :

        void romanType::returnArabic(char roman[]) {
            // ... your code - it will use the arabicNum inside the class here !!
        }


This just after quickly scanning your code. Make the suggested modifications, and see if that helped.
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The while loop & switch should be like this: other wise it never incremented the index and the amount

while(roman[index] != 'Q')
{
      switch (roman[index])
      {
      case 'M': case 'm':
            value = 1000;
            arabicNum = value + arabicNum;
            index++;
            break;
      case 'D': case 'd':
            value = 500;
            arabicNum = value + arabicNum;
            index++;
            break;
      case 'C': case 'c':
            value = 100;
            arabicNum = value + arabicNum;
            index++;
            break;
      case 'L': case 'l':
            value = 50;
            arabicNum = value + arabicNum;
            index++;
            break;
      case 'X': case 'x':
            value = 10;
            arabicNum = value + arabicNum;
            index++;
            break;
      case 'V': case 'v':
            value = 5;
            arabicNum = value + arabicNum;
            index++;
            break;
      case 'I': case 'i':
            value = 1;
            arabicNum = value + arabicNum;
            index++;
            break;
            
            
            
      }//end of switch structure
}//end of while loop

Best Regards,
DeepuAbrahamK
DeepuAbrahamK, that's a bit overkill, isn't it ? You could have suggested something like this :

while(roman[index] != 'Q')
{
      switch (roman[index])
      {
      case 'M': case 'm':
            arabicNum += 1000;
            break;
      case 'D': case 'd':
            arabicNum += 500;
            break;
      case 'C': case 'c':
            arabicNum += 100;
            break;
      case 'L': case 'l':
            arabicNum += 50;
            break;
      case 'X': case 'x':
            arabicNum += 10;
            break;
      case 'V': case 'v':
            arabicNum += 5;
            break;
      case 'I': case 'i':
            arabicNum += 1;
            break;
      }//end of switch structure
      ++index;
}//end of while loop
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