Question

   import java.util.Scanner;


   public class Addition
        {
        public Addition (int x , int y)
        {
         int sum;
         int one = x;
         int two = y;
         sum =x+y;
         System.out.println("Addition of Number:%d" +sum);
         }
         }

         public class Subtraction{
         public  Subtraction(int x ,int y){
         int sub;
         int one = x;
         int two = y;
         sub =x-y;
         System.out.println("Subtraction of Number: %d" +sub);
         }
         }
         public class Multiplication
         {
               public  Multiplication(int x ,int y){
          int mul;
          int one = x;
          int two = y;
          mul =x*y;
          System.out.println("Multiplication of Numbers:%d" +mul);
          }
          } 
          public class Division{
          public  Division(int x , int y){
          int div;
          int one = x;
          int two = y;
          div = x/y;
          }
          }
               public class Calculator
               {
               public static void main(String args[]){
               int one;
               int two;
               String choice;
               System.out.println("Enter numbers to calculate:");
               Scanner input = new Scanner(System.in);
               int one =input.nextInt();
               System.out.println("Your First Number =" +one);
               int two=input.nextInt();
               System.out.println("Your First Number =" +one);
               System.out.println("Enter your choice");
               String choice = input.nextLine();

               switch(choice){
               case Add:      
               Addition A =new Addition(int one ; int two); 
               break;
               case Sub:      
               Subtraction s =new Subtraction(int one; int two); 
               break;
               case Mul:      
               Multiplication m =new Multiplication(int one; int two); 
               break;
               case Div:      
               Division A =new Division(int one; int two); 
               break;
               default:
               System.out.println("Wrong Choice"); 
               break;
                       }
             }
       }

我在做错误的地方告诉我错误：

Calculator.java:55: error: '.class' expected
     Addition a =new Addition(int one ; int two); 
                                  ^
Calculator.java:55: error: ';' expected
     Addition a =new Addition(int one ; int two); 
                                               ^
Calculator.java:58: error: '.class' expected
     Subtraction s =new Subtraction(int one; int two); 
                                        ^
Calculator.java:58: error: ';' expected
     Subtraction s =new Subtraction(int one; int two); 
                                                    ^
Calculator.java:61: error: '.class' expected
     Multiplication m =new Multiplication(int one; int two); 
                                              ^
Calculator.java:61: error: ';' expected
     Multiplication m =new Multiplication(int one; int two); 
                                                          ^
Calculator.java:64: error: '.class' expected
     Division d =new Division(int one; int two); 
                                  ^
Calculator.java:64: error: ';' expected
     Division d =new Division(int one; int two); 
                                              ^

Answer 1

Addition A =new Addition(int one ; int two);

错误正确的是：

Addition A =new Addition(one , two);

这也适用于其他初始化。

专门阅读this 6和7，了解有关函数和函数调用的更多信息，这是简单的可视化教程。

Answer 2

你已经定义了'one'和'two'的类型：

int one =input.nextInt();
int two=input.nextInt();

因此，在调用新对象时，无需在参数列表中重新定义它。所以只要你写下来就可以了。：

Addition A =new Addition(one,two);

或

Subtraction s =new Subtraction(one, two);

参数列表也以逗号分隔。我已经在上面的代码括号中修复了它。

Answer 3

这里有多个错误 1.按照指定在主方法切换案例中创建加法，减法等类的对象时删除分号（;）。即所有案件的以下内容

 Addition A =new Addition(one,two);

2.你在main方法中创建了两个原始的两个。只保留一次。将变量声明保留为int one; int two;字符串选择

将代码更改为

one =input.nextInt();//remove int in the beginning
two=input.nextInt();//remove int in the beginning
choice = input.nextLine();

3.您需要在开关案例中声明“添加”，“子”，“Div”，“Mul”。交换机使用byte，short，char和int原始数据类型。它也适用于枚举类型（在枚举类型中讨论），String类和一些包含某些基本类型的特殊类：Character，Byte，Short和Integer（在Numbers和Strings中讨论）。

import java.util.Scanner;


class Addition
{
public Addition(int x , int y)
{
 int sum;
 int one = x;
 int two = y;
 sum =x+y;
 System.out.println("Addition of Number: " +sum);
 }
 }

 class Subtraction{
 public  Subtraction(int x ,int y){
 int sub;
 int one = x;
 int two = y;
 sub =x-y;
 System.out.println("Subtraction of Number: " +sub);
 }
 }

 class Multiplication
 {
       public  Multiplication(int x ,int y){
  int mul;
  int one = x;
  int two = y;
  mul =x*y;
  System.out.println("Multiplication of Numbers: " +mul);
  }
  } 

 class Division{
  public  Division(int x , int y){
  int div;
  int one = x;
  int two = y;
  div = x/y;
  System.out.println("Division of Numbers: " +div);
  }
  }
  public class Calculator
       {
       public static void main(String args[]){
       int one;
       int two;
       String choice;

       System.out.print("Enter Choice Add / Sub / Mul / Div");

       Scanner input1 = new Scanner(System.in);
       choice = input1.nextLine();

       System.out.println("Enter numbers to calculate:");
       one =input1.nextInt();
       two=input1.nextInt();
       input1.close();
       System.out.println("Your First Number =" +one);
       System.out.println("Your Second Number =" +two);
       System.out.println("Your choice="+choice);

       final String Add = "Add";
       final String Sub = "Sub";
       final String Mul = "Mul";
       final String Div = "Div";

       switch(choice){
       case Add:      
       Addition A =new Addition(one ,two); 
       break;
       case Sub:      
       Subtraction s =new Subtraction(one,two); 
       break;
       case Mul:      
       Multiplication m =new Multiplication(one,two); 
       break;
       case Div:      
       Division d =new Division(one,two); 
       break;
       default:
       System.out.println("Wrong Choice"); 
       break;
               }
     }
}

Answer 4

调用构造函数时必须删除该类型。参数列表以逗号分隔。

Addition A =new Addition(one,two);

请告诉我我在哪里犯错误

4 个答案: