我的 Java 类的作业指示我们获取用户输入的整数(最多 3999)并将其转换为罗马数字。我在代码中遇到的问题是，当我在测试时输入整数时，它将整数设置为 0 并且罗马数字打印为 null。这可能是在对象内部声明变量的结果，但目前我不确定。
public class RomanNumerals
{
// instance variables
int input;
String romanNum;
/**
* Object that records the input from a user.
*/
public RomanNumerals()
{
int input=0;
String romanNum="";
//System.out.println("Input a number to get a Roman Numeral");
//int input = integer.nextInt();
}
public int Scanner()
{
Scanner integer = new Scanner(System.in);
System.out.println("Input a number to get a Roman Numeral: ");
int input = integer.nextInt();
return input;
}
/**
* Object that takes the input from the user and determines what roman numerals are appropriate.
*/
public String Int2Roman()
{
if (input < 1 || input > 3999)
{
System.out.println("Please input a number between 1 and 3999.");
}
while (input >= 1000)
{
romanNum = romanNum + "M";
input = input - 1000;
}
while (input >= 900)
{
romanNum = romanNum + "CM";
input = input - 900;
}
while (input >= 500)
{
romanNum = romanNum + "S";
input = input - 500;
}
while (input >= 400)
{
romanNum = romanNum + "CS";
input = input - 1000;
}
while (input >= 100)
{
romanNum = romanNum + "C";
input = input - 100;
}
while (input >= 90)
{
romanNum = romanNum + "XC";
input = input - 1000;
}
while (input >= 50)
{
romanNum = romanNum + "L";
input = input - 1000;
}
while (input >= 40)
{
romanNum = romanNum + "XL";
input = input - 40;
}
while (input >= 10)
{
romanNum = romanNum + "X";
input = input - 10;
}
while (input >= 9)
{
romanNum = romanNum + "IX";
input = input - 9;
}
while (input >= 5)
{
romanNum = romanNum + "V";
input = input - 5;
}
while (input >= 4)
{
romanNum = romanNum + "IV";
input = input - 4;
}
while (input >= 1)
{
romanNum = romanNum + "I";
input = input - 5;
}
System.out.println("The Roman Numeral of " + input + " is " + romanNum);
return romanNum;
}
public static void main(String[] args)
{
RomanNumerals a = new RomanNumerals();
a.Scanner();
a.Int2Roman();
}
}
最佳答案
您的Scanner方法不会将键盘输入存储在字段(实例变量)input中，而是存储在本地变量input中。
替换
int input = integer.nextInt(); //this declares a new local variable
与
input = integer.nextInt(); //uses the existing field
关于java - 在 Java 中将整数转换为罗马数字，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/60779420/