Java，Double 数据类型有问题，一直返回 1.00 而不是 1.8

Question

这个问题已经有答案了:

How to make the division of 2 ints produce a float instead of another int? (9 个回答)

Int division: Why is the result of 1/3 == 0? (19 个回答)

已关闭 5 年前。

我正在为我的大学开发一个项目，到目前为止，代码运行良好，除了当程序尝试计算所有输入的平均值时，它总是给出错误的答案。前任:测试输入:3-4512-70(退出循环)

结果->总和:9柜台:5平均值 = 1.0 ?应该是1.8

如果有人可以帮忙，请给我一些建议。

public static void main(String[] args) 
{
    Scanner sc = new Scanner(System.in);
    int counter = 0;

    int intInput;
    int intLargest;
    int intSmallest;
    int intEven = 0;
    int intOdd = 0;
    int intSum = 0;
    String strMessage = "Enter a series of value (0 to quit)";    


    System.out.print(strMessage);
    System.out.println();        

   System.out.print("Enter Integer value?" + "\n");
   intInput = sc.nextInt();

        intLargest = intInput;
        if (intLargest == 0)
        {
            intLargest = 0;
        }
        else
        {
            intLargest = intInput;
        }
        /////////////////////////////////////////////////////////////

        intSmallest = intInput;
        if (intSmallest == 0)
        {
            intSmallest = 0;
        }
        else
        {
            intSmallest = intInput;
        }            



    while(intInput != 0)
    { 
    {            
      if (intInput > intLargest)
      {
          intLargest = intInput;
      }//Get the largest value        
      else if (intInput < intSmallest)
      {
          intSmallest = intInput;
      }//Get the smallest value


      if ((intInput%2) == 0)
      {
          intEven++;
      }//Get number of Even value
      else if ((intInput%2) != 0)
      {
          intOdd++;
      }//Get number of Odd value
    }


      intSum = intSum + intInput;        
      intInput = sc.nextInt();
      counter++;
    }

/************************************************/

    double doubleAvg = 0;

    if (counter > 0)
    {
        doubleAvg = intSum / counter;
    }     

/**************************************************** *****/

    System.out.println();
    System.out.print("Smallest = " + intSmallest +"\n");        
    System.out.print("Largest = " + intLargest + "\n");
    System.out.print("Total Entered = " + counter + "\n");        
    System.out.print("Even Number = " + intEven + "\n");
    System.out.print("Odd Number = " + intOdd + "\n");
    System.out.print("Average = " + doubleAvg + "\n");
    System.out.print("SUM: " + intSum + "\n");
}

}

Answer 1

intSum 和 counter 均声明为 int。如果将 int 除以 int，结果也将是 int。所以除法的结果是 1，然后将其转换为 double，得到 1.0。要获得正确的结果，请将 intSum 声明为 double。