import java.util.Scanner; public class Calculator { public static void main(String[] args) { // String expr = "(84 / 4 * 3 - 9) * 2 + 1 / 5"; // 108.2 String expr = new String(" "); Scanner sc = new Scanner(System.in); Parser p; if (args.length == 0) { new GFrame("Calculator"); } else { if (args[0].equals("-n")) { System.out.println("Type \"exit\" or Ctrl+C to exit."); while (true) { System.out.print(">>> "); expr = sc.nextLine(); if (!expr.equals("exit")) { p = new Parser(expr); System.out.println(p.eval()); } else { sc.close(); break; } } } else { } } } }