Thread: Really need help..

Can anyone explain why this code isn't working.. It's supposed to take a year and convert it to roman numerals.. I can't use returns.. "not allowed"..

import java.util.Scanner;
public class threedottwentysix {
	public static void main(String[] args){
	Scanner in = new Scanner(System.in);
	System.out.println("Please Enter a year that is less than 3999: ");
	String input = in.nextLine();
	int digit = input.length();
	String digitOne = "";
	String digitTwo = "";
	String digitThree = "";
	String digitFour = "";
	if (digit == 4){
			int num1 = Integer.parseInt(input.substring(0, 1));
			switch(num1){
			case 1: digitOne = "M"; break;
			case 2: digitOne = "MM"; break;
			case 3: digitOne = "MMM"; break;
                              }
                        }
		else if (digit == 3)
                        { 
			int num2 = Integer.parseInt(input.substring(1,2));
			switch(num2)
                            {
			case 1: digitTwo = "C"; break;
			case 2: digitTwo = "CC"; break;
			case 3: digitTwo = "CCC"; break;
			case 4: digitTwo = "CD"; break;
			case 5: digitTwo = "D"; break;
			case 6: digitTwo = "DC"; break;
			case 7: digitTwo = "DCC"; break;
			case 8: digitTwo = "DCCC"; break;
			case 9: digitTwo = "CM"; break;
                            }
                       }
		else if (digit == 2)
                       {
			int num3 = Integer.parseInt(input.substring(2,3));
			switch(num3)
                             {
			case 1: digitThree = "X"; break;
			case 2: digitThree = "XX"; break;
			case 3: digitThree = "XXX"; break;
			case 4: digitThree = "XL"; break;
			case 5: digitThree = "L"; break;
			case 6: digitThree = "LX"; break;
			case 7: digitThree = "LXX"; break;
			case 8: digitThree = "LXXX"; break;
			case 9: digitThree = "XC"; break;
                           }
                        }
		else if (digit == 1)
                           {
			int num1 = Integer.parseInt(input.substring(3,4));
			switch(num1)
                         {
			case 1: digitFour = "I"; break;
			case 2: digitFour = "II"; break;
			case 3: digitFour = "III"; break;
			case 4: digitFour = "IV"; break;
			case 5: digitFour = "V"; break;
			case 6: digitFour = "VI"; break;
			case 7: digitFour = "VII"; break;
			case 8: digitFour = "VIII"; break;
			case 9: digitFour = "IX"; break;
                            }
                       }
	if (digit == 3)
                  {
			int num2 = Integer.parseInt(input.substring(1,2));
			switch(num2) {
			case 1: digitTwo = "C"; break;
			case 2: digitTwo = "CC"; break;
			case 3: digitTwo = "CCC"; break;
			case 4: digitTwo = "CD"; break;
			case 5: digitTwo = "D"; break;
			case 6: digitTwo = "DC"; break;
			case 7: digitTwo = "DCC"; break;
			case 8: digitTwo = "DCCC"; break;
			case 9: digitTwo = "CM"; break;
                              }
                        }
		else if (digit == 2)
                        {
			int num3 = Integer.parseInt(input.substring(2,3));
			switch(num3)
                              {
			case 1: digitThree = "X"; break;
			case 2: digitThree = "XX"; break;
			case 3: digitThree = "XXX"; break;
			case 4: digitThree = "XL"; break;
			case 5: digitThree = "L"; break;
			case 6: digitThree = "LX"; break;
			case 7: digitThree = "LXX"; break;
			case 8: digitThree = "LXXX"; break;
			case 9: digitThree = "XC"; break;
                             }
                         }
		else if (digit == 1)
                         {
			int num4 = Integer.parseInt(input.substring(3,4));
			switch(num4)
                             {
			case 1: digitFour = "I"; break;
			case 2: digitFour = "II"; break;
			case 3: digitFour = "III"; break;
			case 4: digitFour = "IV"; break;
			case 5: digitFour = "V"; break;
			case 6: digitFour = "VI"; break;
			case 7: digitFour = "VII"; break;
			case 8: digitFour = "VIII"; break;
			case 9: digitFour = "IX"; break;
                               }
                         }
	if (digit == 2)
                {
			int num3 = Integer.parseInt(input.substring(2,3));
			switch(num3)
                                {
			case 1: digitThree = "X"; break;
			case 2: digitThree = "XX"; break;
			case 3: digitThree = "XXX"; break;
			case 4: digitThree = "XL"; break;
			case 5: digitThree = "L"; break;
			case 6: digitThree = "LX"; break;
			case 7: digitThree = "LXX"; break;
			case 8: digitThree = "LXXX"; break;
			case 9: digitThree = "XC"; break;
                              }
                        }
		else if (digit == 1) 
                        {
			int num4 = Integer.parseInt(input.substring(3,4));
			switch(num4)
                              {
			case 1: digitFour = "I"; break;
			case 2: digitFour = "II"; break;
			case 3: digitFour = "III"; break;
			case 4: digitFour = "IV"; break;
			case 5: digitFour = "V"; break;
			case 6: digitFour = "VI"; break;
			case 7: digitFour = "VII"; break;
			case 8: digitFour = "VIII"; break;
			case 9: digitFour = "IX"; break;
                             }
                        }
	if (digit == 1)
                        {
			int num4 = Integer.parseInt(input.substring(3,4));
			switch(num4)
                               {
			case 1: digitFour = "I"; break;
			case 2: digitFour = "II"; break;
			case 3: digitFour = "III"; break;
			case 4: digitFour = "IV"; break;
			case 5: digitFour = "V"; break;
			case 6: digitFour = "VI"; break;
			case 7: digitFour = "VII"; break;
			case 8: digitFour = "VIII"; break;
			case 9: digitFour = "IX"; break;
                               }
                        }
	System.out.print(digitOne + digitTwo + digitThree + digitFour);
	}	
}

output:
Please Enter a year that is less than 3999:
1962
M

See, my prof. taught us nested if statements and told me to do it that way.. I honestly don't know the correct format in nested switch statements.. I have a Java book but really isn't helpful for more complicated problems.. well.. complicated being relative..

When you say the "hardcoded values," do you mean the int num1 = Integer.parseInt(input.substring(1,2);? Isn't num1 considered a variable?