Java作业，设计一个计算器。

作业：写一个计算器，要求实现加减乘除功能，并且能够循环接受新的数据，通过用户交互实现。

思路推荐:

• 写4个方法：加，减，乘，除

• 利用循环+switch进行用户交互

• 传递需要交互的两个数

• 输出结果

  我自己写了一个简单类似的程序

  package com.kuang.method;
  
  public class Demo05 {
      public static void main(String[] args) {
          int add = add(2, 3);
          System.out.println(add);
          int sub = sub(2, 3);
          System.out.println(sub);
          int multi = multi(2, 3);
          System.out.println(multi);
          int div = div(2, 3);
      }
  
      public static int add(int a, int b) {
          int result = 0;
          System.out.println(a + b);
          return result;
      }
  
      public static int sub(int a, int b) {
          int result = 0;
          System.out.println(a - b);
          return result;
      }
  
      public static int multi(int a, int b) {
          int result = 0;
          System.out.println(a * b);
          return result;
      }
  
      public static int div(int a, int b) {
          if (b == 0) {
              System.out.println("分母不能为0");
          } else {
              int result = 0;
              System.out.println(a / b);
              return result;
          }
          return a;
      }
  }
  

  正确操作

  package com.kuang.method;
  
  import java.util.Scanner;
  
  public class Demo06 {
      public static void main(String[] args) {
          Scanner scanner = new Scanner(System.in);
          while (scanner.hasNextDouble()) {
              double a = scanner.nextDouble();
              String b = scanner.next();
              double c = scanner.nextDouble();
              switch (b) {
                  case "+":
                      add(a, c);
                      break;
                  case "-":
                      minus(a, c);
                      break;
                  case "*":
                      multiply(a, c);
                      break;
                  case "/":
                      except(a, c);
                      break;
              }
              System.out.println("输入任意字母退出");
          }
          scanner.close();
  
      }
  
      public static void add(double a, double b) {
          System.out.println(a + b);
  
      }
  
      public static void minus(double a, double b) {
          System.out.println(a - b);
      }
  
      public static void multiply(double a, double b) {
          System.out.println(a * b);
      }
  
      public static void except(double a, double b) {
          if (b == 0) {
              System.out.println("分母不能为0");
          } else {
              System.out.println(a / b);
          }
  
      }
  }