计算函数count

public class CounterFunction {

 public static void main(String[] args) {
  // TODO Auto-generated method stub
  run();
 }

 public static void run() {
  Scanner sc = new Scanner(System.in);
  System.out.println("输入俩个算数: ");
  double a = sc.nextDouble();
  double b = sc.nextDouble();
  System.out.println("请选择您的操作:\n\t a add加法操作\n\t b substrace减法操作\n\t "
    + "c ride乘法操作\n\t d except除法操作\n\t e 退出操作\n\t");
  while (true) {
   char operator = sc.next().toCharArray()[0];
   count(operator, a, b);
  }
 }

 public static void count(char operator, double a, double b) {
  switch (operator) {
  case 'a':
   add(a, b);
   break;
  case 'b':
   subtrace(a, b);
   break;
  case 'c':
   ride(a, b);
   break;
  case 'd':
   except(a, b);
   break;
  case 'e':
   System.out.println("所有的操作结果为: ");
   add(a, b);
   subtrace(a, b);
   ride(a, b);
   except(a, b);
   System.exit(0);
  default:
   System.out.println("    您输入的操作选项有误!!!  \n\t  请重新输入选项");
  }
 }

 public static void add(double a, double b) {
  double aa = a + b;
  System.out.println("加法操作\n结果: " + a + "*" + b + "=" + aa);
  // return aa;
 }

 public static void subtrace(double a, double b) {
  double bb = a - b;
  System.out.println("减法操作\n结果: " + a + "-" + b + "=" + bb);
 }

 public static void ride(double a, double b) {
  double cc = a * b;
  System.out.println("乘法操作\n结果: " + a + "*" + b + "=" + cc);
 }

 public static void except(double a, double b) {
  double dd = a / b;
  System.out.println("您选择的除法操作\n结果: " + a + "/" + b + "=" + dd);
 }
}