Question

是的，我知道这里有很多方法。这是任务的一部分。在这个代码中，一切都按预期工作，除了输入等于和<= 100的数字时，“平均”输出是错误的。例如：如果我输入8,10,19并且零输出则输出计数3总和37平均值9.25 ....平均值应为12.3333。现在，如果我输入8,10,99输出是计数3总和117和平均值39这是正确的。为什么它的总和> 100而不是总和＆lt; = 100 ???我不明白。我错过了什么？

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) {
        if (input!=0){
            counter++;
        }
        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));
        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
                average = (avg(theSum, counter));    
                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, float num2) {
    //Declare and initialize variable for average
    //Calculate average
    float 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);
    }

}

}

Answer 1

原因是你以不同的方式退出while循环，具体取决于总和。如果总和小于100，即使您输入数字0到“退出”，您仍然需要额外的时间。说实话，整个循环需要完全重组;一个do...while循环将更容易阅读和调试。

Answer 2

你的柜台比必要的大1。除以(counter - 1)将解决它。

Answer 3

问题是因为@chrylis提到的退出while循环的方式。因此，如果总和为<= 100，则计数器为1。但是当你打印它时，你会得到正确的结果，因为你在这里更新了计数器值：

if (sum <= 100) {
        JOptionPane.showMessageDialog(null, "Count = " + (counter - 1) + ", Sum = " + sum + ", Average = " + average);
    }

正如您在示例中所看到的： “如果我输入8,10,19并且零以退出输出count 3 sum 37 average 9.25”

这是因为计数器值为4（因此平均值为37/4 = 9.25），但在显示结果时，您将计数器减1，因此计数为3

do-while循环将解决问题，因为最后会检查条件，因此循环将以相同的方式退出<=100和'＆gt; 100`。

do-while循环将是这样的：

do{

//here goes your code

}while (input != 0);

我的方法平均有什么问题？

3 个答案: