当用户输入句点时停止的 Java 计算器程序

Question

说明:修改您的程序，以便用户能够将操作链接在一起。输入一个整数、运算符，然后输入另一个整数不应再自动结束程序。向用户显示第一个运算的结果后，允许用户输入另一个运算，然后输入另一个整数。然后，程序应使用第一个运算的结果作为运算左侧的整数，并将新输入的整数作为运算右侧的整数。显示结果后，用户应该能够键入句点 (.) 来结束程序。输入句点后，程序应打印出消息:“程序已关闭。”

需要帮助弄清楚如何在用户输入一个句点时使程序停止我尝试通过 do-while 来做到这一点示例:3+5结果:8+3结果:11-5结果:6。该计划已关闭。

请帮忙

import java.util.Scanner;
class Main {
    static final String VERSION = "1.0";
    public static void main(String[] args) {

    public static void printCalculatorInstructions(){
          System.out.println("Welcome to version "+VERSION+" of the Calculator.");
          System.out.println("In order to use the calculator, do the following:");
          System.out.println("1. Enter the integer that is left of the operator.");
          System.out.println("2. Press enter.");
          System.out.println("3. Enter an operation. Available operations are:\n\t + (addition) \n\t - (subtraction) \n\t * (multiplication) \n\t / (division) \n\t % (remainder) \n\t ^ (exponentiation)");
          System.out.println("4. Press enter.");
          System.out.println("5. Enter the integer to the right of the operator.");
          System.out.println("6. Press enter.");
          System.out.println("7. Look at the result that is printed out!");
      }

        printCalculatorInstructions();

        // Get input for calculator
        Scanner keyboard = new Scanner(System.in);
        int num1 = keyboard.nextInt();
        keyboard.nextLine(); //clear line break character: \n
        String operator = keyboard.nextLine();
        int num2 = keyboard.nextInt();
        int loop = 0;

        do
        {
          //Call the method to perform the calculation based on what operation needs to be used
          if(operator.equals("+")){
            addition(num1, num2);
          }else if(operator.equals("-")){
            subtraction(num1, num2);
          }//you will need to write more else if statements as you implement each of the operators
          else if (operator.equals("*")){
            multiplication(num1, num2);
          }
          else if (operator.equals("/")){
            division(num1, num2);
          }
          else if (operator.equals("%")){
            modulardivision(num1, num2);
          }
          else if (operator.equals("^")){
            exponentiation(num1, num2);
          }

      public static int addition(int a, int b){
          int result = a + b;
          System.out.println("Result: " + result);
          return result;
          result = result +
      }

      public static int subtraction(int a, int b){
          //fill in method here
          int result = a - b;
          System.out.println("Result: " + result);
          return result;
      }

      //write the next method for multiplication here.
      public static int multiplication(int a, int b){
        int result = a * b;
        System.out.println("Result: " + result);
        return result;
      }

      //Then write the methods for division, the % operator, and finally exponentiation.
      public static int division(int a, int b){
        int result = a / b;
        System.out.println("Result: " + result);
        return result;
      }

      public static int modulardivision(int a, int b){
        int result = a % b;
        System.out.println("Result: " + result);
        return result;
      }

      public static double exponentiation(double a, double b){
        double result = Math.pow(a,b);
        System.out.println("Result: " + result);
        return result;
      }


      if (a == .) {
        int loop = 1;
      }

       } while (loop != 1);
}

/* retrun result;
void = nothing is being return   void ! = addition*/ ```

Answer 1

您的代码存在严重的语法问题。

<小时/>

试试这个:

import java.util.Scanner;

public class Calculator {
    static final String VERSION = "1.0";

    public static void printCalculatorInstructions(){
        System.out.println("Welcome to version "+VERSION+" of the Calculator.");
        System.out.println("In order to use the calculator, do the following:");
        System.out.println("1. Enter the integer that is left of the operator.");
        System.out.println("2. Press enter.");
        System.out.println("3. Enter an operation. Available operations are:\n\t + (addition) \n\t - (subtraction) \n\t * (multiplication) \n\t / (division) \n\t % (remainder) \n\t ^ (exponentiation)");
        System.out.println("4. Press enter.");
        System.out.println("5. Enter the integer to the right of the operator.");
        System.out.println("6. Press enter.");
        System.out.println("7. Look at the result that is printed out!");
    }

    public static int addition(int a, int b){
        int result = a + b;
        System.out.println("Result: " + result);
        return result;
    }

    public static int subtraction(int a, int b) {
        int result = a - b;
        System.out.println("Result: " + result);
        return result;
    }

    public static int multiplication(int a, int b) {
        int result = a * b;
        System.out.println("Result: " + result);
        return result;
    }

    public static int division(int a, int b) throws ArithmeticException {
        int result = a / b;
        System.out.println("Result: " + result);
        return result;
    }

    public static int modulardivision(int a, int b) {
        int result = a % b;
        System.out.println("Result: " + result);
        return result;
    }

    public static double exponentiation(double a, double b) {
        double result = Math.pow(a, b);
        System.out.println("Result: " + result);
        return result;
    }   

    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);

        boolean toStop = false;

        while (toStop == false) {
            printCalculatorInstructions();

            int num1 = keyboard.nextInt();
            keyboard.nextLine(); //clear line break character: \n
            String operator = keyboard.nextLine();
            int num2 = keyboard.nextInt();

            switch (operator) {
            case "+":
                addition(num1, num2);
                break;
            case "-":
                subtraction(num1, num2);
                break;
            case "*": 
                multiplication(num1, num2);
                break;
            case "/":
                try {
                    division(num1, num2); // in case value of num2 is zero, this won't terminate the program
                } catch (ArithmeticException e) {
                    System.out.println("Value of num2 was zero. Enter a non-zero value for num2.");
                }
                break;
            case "%":
                modulardivision(num1, num2);
                break;
            case "^":
                exponentiation(num1, num2);
                break;
            default:
                toStop = true; // any other operator, character or string entered here will stop the loop
                break;
            }
        }

        keyboard.close();
    }
}

我做了一个 while 循环，一直运行到 boolean 条件 toStop == false 变得不正确，即 toStop 的值变为 true。当用户输入不是您提到的运算符时，该值将发生更改。我没有使用 if-else 语句，而是使用 switch 语句来使该过程易于遵循。

我希望这有帮助。