Question

Write a JAVA program to input a number and print that number in Roman Numerals . Number should be entered using SCANNER class .

Answer 1

java methods roman-numerals

This is a homework assignment I am having trouble with.

I need to make an integer to Roman Numeral converter using a method. Later, I must then use the program to write out 1 to 3999 in Roman numerals, so hardcoding is out. My code below is very bare-bones; it is a basic I/O loop with a way to exit while using a package for getIntegerFromUser we made in class.

Is there a way to assign values to Strings and then add them together when I call the method?

Update: I got some pseudo code from my professor to help me, and while I understand what he is trying to say, I am having some trouble with the ifs. Will I be needing many, many if statements so that my converter will correctly handle the Roman numeral formatting or is there a manner in which I can do this with more efficiency? I've updated my code to reflect my placeholder method.

Update (Oct 28 2012): I got it working. Here's what I ended up using:

public static String IntegerToRomanNumeral(int input) { if (input < 1 || input > 3999) return "Invalid Roman Number Value"; String s = ""; while (input >= 1000) { s += "M"; input -= 1000; } while (input >= 900) { s += "CM"; input -= 900; } while (input >= 500) { s += "D"; input -= 500; } while (input >= 400) { s += "CD"; input -= 400; } while (input >= 100) { s += "C"; input -= 100; } while (input >= 90) { s += "XC"; input -= 90; } while (input >= 50) { s += "L"; input -= 50; } while (input >= 40) { s += "XL"; input -= 40; } while (input >= 10) { s += "X"; input -= 10; } while (input >= 9) { s += "IX"; input -= 9; } while (input >= 5) { s += "V"; input -= 5; } while (input >= 4) { s += "IV"; input -= 4; } while (input >= 1) { s += "I"; input -= 1; } return s; }