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axel609 (48)
i can't get this function working

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#include <iostream>
#include <string>
#include <cctype>
#include <iomanip>
using namespace std;

int convert_digit(string roman);



int main()
{
	string roman;
	char goAgain;
	

do
{
	cout << "Please enter the Roman Numeral to convert : ";
	cin >> roman;
	
    convert_digit (string roman);
   
 
 cout << "Roman Number " << roman << " equals " << sum <<endl;
 cout << "Want to convert Roman Numeral again(Y or N)";
 cin >> goAgain;

while(toupper(goAgain) !='Y' && toupper(goAgain) !='N')
{
  cout << "please enter Y or N: ";
  cin >> goAgain;
}
	
}while(toupper(goAgain) =='Y');

return 0;
}


int convert_digit(string roman)
{
    	int length = roman.length();
		int previous = 0;
		bool error = false;
		int nIndex = 0;

		int sum = 0;

		while( (error == false) && (nIndex < length) )
		{
			switch(roman[nIndex])
			{
			case 'M':
				sum += 1000;
				if(previous < 1000)
				{
					sum -= 2 * previous;
				}
				previous = 1000;
				break;
			case 'D':
				sum += 500;
				if(previous < 500)
				{
					sum -= 2 * previous;
				}
				previous = 500;
				break;
			case 'C':
				sum += 100;
				if(previous < 100)
				{
					sum -= 2 * previous;
				}
				previous = 100;
				break;
			case 'L':
				sum += 50;
				if(previous < 50)
				{
					sum -= 2 * previous;
				}
				previous = 50;
				break;
			case 'X':
				sum += 10;
				if(previous < 10)
				{
					sum -= 2 * previous;
				}
				previous = 10;
				break;
			case 'V':
				sum += 5;
				if(previous < 5)
				{
					sum -= 2 * previous;
				}
				previous = 5;
				break;
			case 'I':
				sum += 1;
				if(previous < 1)
				{
					sum -= 2 * previous;
				}
				previous = 1;
				break;
			default:
				cout << roman[nIndex] << " is not a Roman Numeral!" << endl;
				error = true;
				sum = 0;
			} // switch

			nIndex++;

		} // while 
		return sum;
    
}
keskiverto (10402)
Please explain the "not working" in detail.
axel609 (48)
int convert_digit is not converting roman numeral to numbers
keskiverto (10402)
How can you know that? The code that you show does not even compile due to errors on lines 23 and 26.
axel609 (48)
got convert_digit to work however i added a new function called check_format and an error: expected primary-expression before 'roman' on line 21. any advice

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#include <iostream>
#include <string>
#include <cctype>
#include <iomanip>
using namespace std;

int convert_digit(string roman);
bool check_format( string []);


int main()
{
string roman;
char goAgain;

do
{
  cout << "Please enter the Roman Numeral to convert : ";
  cin >> roman;
    
   if (check_format(string roman))
   {
  cout << "Roman Number " << roman << " equals " << convert_digit(roman) <<endl;
   }
  else
  {
   cout << "That is not the proper format for Roman Numerals";   
  }      
  cout << "Want to convert Roman Numeral again(Y or N)";
  cin >> goAgain;

while(toupper(goAgain) !='Y' && toupper(goAgain) !='N')
{
  cout << "please enter Y or N: ";
  cin >> goAgain;
}
}while(toupper(goAgain) =='Y');
return 0;
}


int convert_digit(string roman)
{
    int length = roman.length();
int previous = 0;
bool error = false;
int nIndex = 0;

int sum = 0;

while( (error == false) && (nIndex < length) )
{
switch(roman[nIndex])
{
case 'M':
sum += 1000;
if(previous < 1000)
{
sum -= 2 * previous;
}
previous = 1000;
break;
case 'D':
sum += 500;
if(previous < 500)
{
sum -= 2 * previous;
}
previous = 500;
break;
case 'C':
sum += 100;
if(previous < 100)
{
sum -= 2 * previous;
}
previous = 100;
break;
case 'L':
sum += 50;
if(previous < 50)
{
sum -= 2 * previous;
}
previous = 50;
break;
case 'X':
sum += 10;
if(previous < 10)
{
sum -= 2 * previous;
}
previous = 10;
break;
case 'V':
sum += 5;
if(previous < 5)
{
sum -= 2 * previous;
}
previous = 5;
break;
case 'I':
sum += 1;
if(previous < 1)
{
sum -= 2 * previous;
}
previous = 1;
break;
default:
cout << roman[nIndex] << " is not a Roman Numeral!" << endl;
error = true;
sum = 0;
} // switch

nIndex++;

} // while 
return sum;
    
}




bool check_format( string roman)
{
    
    if (roman.find_first_of("IIII") !=string::npos)
    {
        return false;
     }
    else if (roman.find_first_of("XXXX") !=string::npos)
    {
        return false;
     }
     
    else if (roman.find_first_of("LLLL") !=string::npos)
    {
        return false;
     }
     else if (roman.find_first_of("VVVV") !=string::npos)
    {
        return false;
     }
     
    else if (roman.find_first_of("CCCC") !=string::npos)
    {
        return false;
     }
     else if (roman.find_first_of("DDDD") !=string::npos)
    {
        return false;
     }
return true;
}
keskiverto (10402)
What do you have on line 21 before the word "roman" and why?


Compare also lines 8 and 127. That mismatch will be your next error.
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