Program is Chopping off First Interger

Question

I have this method which is supposed to convert roman numerals into integers, however when I put in roman numerals it chops off the first letter, so when I put in "IV", I get 5 rather than 4. Earlier I had the same issue, but only it was chopping off the last letter, but I fixed it. Here is the method pasted below. Thank you. Also please let me know if you notice any other errors.

     public int romanToArabic()
    {
    int sum = 0;
    int i;
    for(i=0; i<=roman.length()-1; i++)
    {

        char rom = roman.charAt(i);
        switch(rom)
        {
            case 'M': 
            sum += 1000;
            break;

            case 'D': 
            sum += 500;
            break;

            case 'C':
            if(i < roman.length()-1)
            {
                char next = roman.charAt(i+1);
                if(next == 'M')
                {
                    sum += 900;
                    i++; 
                }
                if(next == 'D')
                {
                    sum +=400;
                    i++;
                }
                else
                {
                    sum += 100;
                }

            }
            else 
            {
                sum += 100;
            }
            break;

            case 'L':
            sum += 50;
            break;

            case 'X':
            if(i < roman.length()-1)
            {
                char next = roman.charAt(i+1);

                if(next == 'L')
                {
                    sum += 40;
                    i++;
                }
                if(next == 'C')
                {
                    sum += 90;
                    i++;
                }
                else
                {
                    sum += 10;
                }
            }
            else
            {
                sum += 10;
            }
            break;

            case 'V':
            if( i < roman.length()-1)
            {

                char next = roman.charAt(i+1); 

                if(next == 'I')
                {
                    sum += 6;
                    i++;
                }
                else
                {
                    sum += 5;
                }
            }

            else
            {
                sum += 5;
            }
            break;

            case 'I':
            if(i < roman.length()-1)
            {
                char next = roman.charAt(i+1);
                if(next == 'V')
                {
                    sum += 4;
                    i++;
                }
                if(next == 'X')
                {
                    sum += 9;
                    i++;
                }
                else 
                {
                    sum += 1;
                }
            }
            else 
            {
                sum += 1;
            }
            break;

            default: 
            System.out.println("I've encountered an issue with the characters you've entered.");

           }
          }
           return sum;
          }

Answer 1

It looks like you're missing an else. It's not really "chopping" off the first integer, but it may seem that way since sum += 1 will be called when it shouldn't -- e.g., turning a 4 into a 5.

if (next == 'V') {
    sum += 4;
    i++;
} else if (next == 'X') {  // note the else here...
    sum += 9;
    i++;
} else {
    sum += 1;
}

You may have the same mistake for the other cases as well.