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 if
s. 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;
}
StringBuilder
. – CruceString s1 = "Hello"; String s2 = "world"; System.out.println(s1 + " "+ s2);
. Given the fact that this is a homework, you should concatenate theString
s as in the provided code. Otherwise, if you're thinking on performance and best practices, you should use theStringBuilder
as stated in Andrew Thompson's comment. – Stelly