-5

当我运行此代码并输入总和> 100 的数字时，输出对于计数和总和是正确的，但平均值是错误的。例如; 输入 8,10,99...计数为 3，总和为 117，应返回平均值 39...返回的实际输出为计数 3，总和为 117，平均值为 58.5。我开始意识到这是因为平均值是使用 2 而不是 3 的计数来完成的（或者总是比它应该使用不同的值小一）。为什么是这样？它非常适合输入总和<=100。请帮忙 ：）

 public static void main(String[] args) {
    //Use Main Method for gathering input
    float input = 1;
    // Declare variable for sum
    float theSum = 0;
    // Declare variable for average
    float average = 0;
    // Declare variable for counting the number of user inputs
    int counter = 0;
    /* Initialize the while loop using an input of 0 as a sentinel value
     * to exit the loop*/
    while (input != 0) {
        // Use JOptionPane method to accept input from user
        input = Float.parseFloat(
                JOptionPane.showInputDialog(
                null, "Please enter a number.  Enter 0 to quit: "));
        // Invoke sum method and pass input and summation to sum method
        theSum = (sum(input, theSum));
        // Invoke avg method and pass summation and counter to avg
        average = (avg(theSum, counter));
        // Increment the counter variable
        counter++;

        if (theSum > 100)
        {
            JOptionPane.showMessageDialog(null, "The sum of your numbers "
                    + "are greater than 100!");
            break;
        }
    }
        // Invoke display method and pass summation, average, and counter variables to it
        display(theSum, average, counter);
    }


public static float sum(float num1, float sum) {
    //Add the user's input number to the sum variable
    sum += num1;
    //Return value of sum variable as new summation variable
    return sum;
}

public static float avg(float num1, int num2) {
    //Declare and initialize variable for average
    float average = 0;
    //Calculate average
    average = num1 / num2;
    //Return value of average variable
    return average;
}

public static void display(float sum, float average, int counter) {

    /* I am subtracting 1 from variable counter so as not to include the sentinel value
     * of 0 that the user had to enter to exit the input loop in the overall count*/

    // Display the count, sum, and average to the user
    if (sum > 100) {
        JOptionPane.showMessageDialog(null, "Count = " + (counter) + ", Sum = " + sum + ", Average = " + average);
    }
    if (sum <= 100) {
        JOptionPane.showMessageDialog(null, "Count = " + (counter - 1) + ", Sum = " + sum + ", Average = " + average);
    }

}

}

4

1 回答 1

1

您在取平均值后增加计数器，这就是为什么您看到基于 2 个数字而不是预期的 3 个数字的平均值。

    average = (avg(theSum, counter));
    // Increment the counter variable
    counter++;

在取平均值之前交换这两个并增加计数器。

    counter++;
    // Increment the counter variable
    average = (avg(theSum, counter));

编辑：

以下是您应该更改的内容：

首先，仅当输入不 = 0 时才更新计数器

    if(input!=0)
    {
    counter++;
    }

其次，将平均代码移出循环并在显示之前将其放在最后，不需要一次又一次地计算平均值。

    average = (avg(theSum, counter));
    display(theSum, average, counter);

第三，counter-1从display方法中删除并打印counter

public static void display(float sum, float average, int counter) {
 JOptionPane.showMessageDialog(null, "Count = " + (counter) + ", Sum = " + sum + ", Average = " + average);
 }

之后，它适用于您期望的两种情况

于 2013-09-14T03:17:05.913 回答