如何将输入算术运算符存储在Java中的动作变量中

Question

我正在创建基本计算器，要求用户输入第一个值、最后一个值和操作，例如 +、- 、* 这是代码

   Scanner input= new Scanner(System.in);

   double firstval, lastval,result;
    
   Scanner cal = new Scanner(System.in);
   
   System.out.println("Please enter the first value ? ");
   firstval= cal.nextDouble();
   
   System.out.println("Please enter the last value ? ");
   lastval= cal.nextDouble();
   
   System.out.println("Please enter the action ? ");
   // how to store action ( +, - ,*) in varibale to perform result  ?
   String action = cal.next();   
   
   result= firstval + action + lastval; 
   
   System.out.println(result);

谢谢您并期待积极的回应

Answer 1

尝试使用

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

代替扫描仪。