Function needs to return the correct value in C++

[nuken]

the output looks likenthis:

[whodgson]

Where do you convert Roman numerals to decimal values?

[donbock]

Lines 22-36 need to be an if-elseif-else cascade or, better yet, a switch statement. Instead you have sequential if statements -- that means that the last if statement overrides all of the others. Your Roman_digit_Val ue function will only ever return either M or bad_val.

I presume I, V, X, L, C, D, M are all macros. Presumably bad_val is some negative number.

[nuken]

This whole program really seems to be confusing me. Yes,
I, V, X, L, C, D, M are const integers. And by if else cascade means: (we cant use switch)

int Roman_digit_Value( char roman_digit )
{
   int val;
   if ( roman_digit == 'I' )
      val = I;
   else if ( roman_digit == 'V' )
      val = V;
   else if ( roman_digit == 'X' )
      val = X;
   else if ( roman_digit == 'L' )
      val = L;
   else if ( roman_digit == 'C' )
      val = C;
   else if ( roman_digit == 'D' )
      val = D;
   else if ( roman_digit == 'M' )
      val = M;
   else 
       val = bad_val;
   return val;
}
 

If I put the whole program on here could you help me fix it up its like 5 functions or so?

[donbock]

nuken wrote ...

And output should look like this:
MCCXXVI
The first number is 1226
LXVIIII
The second number is 69

The second example uses "VIIII" for 9 instead of "IX". Does this mean that you are not required to support the subtractive format for Roman Numerals?

[nuken]

Yes, I am using only the additive form. Heres some more info.
I = 1
V = 5
X = 10
L = 50
C = 100
D = 500
M = 1000
bad_val = -1

What is confusing me is how to use the basic functions i made to read each letter, change it to a number, add all the numbers together, and then display that number. It also has to do some eqautions but i think i can figure that part out after this first part.
I have to add in there somewhere "The second number is " also.

[nuken]

They are converted using a combination of the two functions. But I changed it a little how do i add all the numbers together before they are displayed?

int Roman_digit_Value( char roman_digit )
{
   int val;
   if ( roman_digit == 'I' )
      val = I;
   else if ( roman_digit == 'V' )
      val = V;
   else if ( roman_digit == 'X' )
      val = X;
   else if ( roman_digit == 'L' )
      val = L;
   else if ( roman_digit == 'C' )
      val = C;
   else if ( roman_digit == 'D' )
      val = D;
   else if ( roman_digit == 'M' )
      val = M;
   else 
       val = bad_val;
   return val;
}
int Get_Roman_Numeral()
{
   int num = 0;
   char ch = 0;
 
   cin >> ch; 
   int value = Roman_digit_Value(ch);
   if ( value > 0 )
   {
      num = num + value;
      return num;
   }
 
 return 0;  
}
 
int main()
{ 
  char operation = '+';
  string input_Roman;  
  int Roman_Num = 0;
  int Second_Roman_Num = 0;
  int Result = 0;
  Roman_Num = Get_Roman_Numeral();
  cout << "The first number is " << endl;
      while ( !cin.eof() ) 
      {  
 
 
         Second_Roman_Num = Get_Roman_Numeral();
         cout << "The second number is " << endl;
         cin >> operation;
         //cout << "Arithmetic operation is " << operation << endl;
         //Result = Return_Operation (Second_Roman_Num, Roman_Num, operation);
         //Print_Result( Roman_Num, Second_Roman_Num, Result, operation );
 
      }
      return 0;
}