// This is how we set things up to read lines of text from the user.
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
// Loop forever
for(;;) {
// Display a prompt to the user
System.out.print("FactQuoter> ");
// Read a line from the user
String line = in.readLine();
// If we reach the end-of-file,
// or if the user types "quit", then quit
if ((line == null) || line.equals("quit")) break;
// Try to parse the line, and compute and print the factorial
try {
int x = Integer.parseInt(line);
System.out.println(x + "! = " + Factorial4.factorial(x));
}
// If anything goes wrong, display a generic error message
catch(Exception e) { System.out.println("Invalid Input"); }
}
