3) To display Roman Equivalent of decimal number using O-O and Command Line Arguments

 source code name:  RomanConversionDemo.java

class RomanConversionDemo
{
void roman(int n, char ch)
{
for(int i=1;i<=n;i++)
System.out.print(ch+" ");
}

public static void main(String[] arg)
 {
int th=0,fh=0,h=0,ft=0,ten=0,fv=0,s=0;
int n;
RomanConversionDemo ob=new RomanConversionDemo();

n=Integer.parseInt(arg[0]);

th=n/1000;
ob.roman(th,'M');
n=n%1000;

fh=n/500;
ob.roman(fh,'D');
n=n%500;

h=n/100;
ob.roman(h,'C');
n=n%100;

ft=n/50;
ob.roman(ft,'L');
n=n%50;

ten=n/10;
ob.roman(ten,'X');
n=n%10;

fv=n/5;
ob.roman(fv,'V');
n=n%5;

s=n;
ob.roman(s,'I');

 }
} 

output:

F:\Nalawade\java1819>javac RomanConversionDemo.java

F:\Nalawade\java1819>java RomanConversionDemo
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
        at RomanConversionDemo.main(RomanConversionDemo.java:16)

F:\Nalawade\java1819>java RomanConversionDemo  1500
M D
F:\Nalawade\java1819>java RomanConversionDemo  1988
M D C C C C L X X X V I I I
F:\Nalawade\java1819>java RomanConversionDemo  2345
M M C C C X X X X V