Question

对于我的任务，我要制作一个程序，从文本文件中读取和打印数字，然后计算这些数字的总和和平均值。我的程序做得很好。我唯一的问题是程序不会读取我的文本文件中的最后一个数字。文件上的数字为：

由于某种原因，计算机无法读取数字4.

这是我的计划：

{ //begin testshell 
public static void main (String[] args)
{ //begin main
    System.out.println("Scores");
    Scanner inFile=null;
    try
    {
        inFile = new Scanner(new File("ints.dat"));
    }
    catch (FileNotFoundException e) 
        {
        System.out.println ("File not found!");
        // Stop program if no file found
        System.exit (0);
        }

   // sets sum at 0 so numbers will be added
   int sum=0;

   int num= inFile.nextInt();

   // starts counting the amount of numbers so average can be calculated
   int numberAmount=0;

    while(inFile.hasNext()) 
    {       
        // print the integer
        System.out.println(num);

        // adds the number to 0 and stores the new number into the variable sum
        sum = num+sum;

        // increases the number of numbers 
        numberAmount++;
        // reads the next integer
        num = inFile.nextInt();
    }
    inFile.close();
    // calculates average
    double average = (double)sum/(double)numberAmount;
    average = Math.round (average * 100.0) / 100.0;  

    //output
    System.out.println("The sum of the numbers = "+sum);
    System.out.println("The number of scores = "+numberAmount);
    System.out.println("The average of the numbers = "+average);

    }//end main
}//end testshell

Answer 1

程序读取最后一个数字，但不使用它，看看这部分：

while(inFile.hasNext()) 
{       
    // ...
    sum = num+sum;

    // reads the next integer
    num = inFile.nextInt();
}

读取最后一个号码，但从未添加到sum。

您需要重新排序语句：

while (inFile.hasNext()) {       
    int num = inFile.nextInt();

    System.out.println(num);

    sum += num;

    numberAmount++;
}

计算机无法从文本文件中读取最后一个数字

1 个答案: