Question

此程序应采用用户定义的数字，创建该大小的数组，并让用户使用do..while循环输入元素 - 即成绩。然后，程序需要显示从最低到最高输入的所有成绩，累积成绩，并找到平均值。

我的输出没有正确显示输入的成绩（如果我输入10,20,30，它显示00,10,20）我无法弄清楚我做错了什么。有什么帮助吗？

import java.util.Arrays;
import java.util.Scanner;

public class LoopArray
{
    public static void main(String[] arg)
    {
        Scanner keyboard = new Scanner(System.in);

        int count = 0;
        double totalAverage = 0;
        double gradesTotal = 0;

        System.out.println("Please input the number of grades you would like to submit for an average: ");
        int numberOfGrades = keyboard.nextInt();                 

        int[] studentScores = new int[numberOfGrades];

        do
        {
            System.out.println("Please enter grade for averaging: ");
            int inputGrade = keyboard.nextInt();
            count++;
            gradesTotal += inputGrade;

        } while (count < numberOfGrades);

        Arrays.sort(studentScores);

        for(count=0; count < studentScores.length; count++)
        {
           System.out.println("Grades entered were: " + count + studentScores[count]);
        }

        totalAverage = gradesTotal / numberOfGrades;
        System.out.println("The total of all grades entered is: " + gradesTotal);
        System.out.println("The average of grades entered is: " + totalAverage);

    }
}

Answer 1

结果

Grades entered were: 00
Grades entered were: 10
Grades entered were: 20

是用

生成的

System.out.println("Grades entered were: " + count + studentScores[count]);

因此，每行中的最后一个数字是代表count + studentScores[count]的对。这意味着：

00 - ＆gt;位置0数组studentScores存储0。
10 - ＆gt;位置1数组studentScores存储0
20 - ＆gt;位置2数组studentScores存储0

这意味着您没有使用用户的值填充studentScores数组。

Answer 2

因为count从0开始。你应该检查它。

Answer 3

您没有在数组中添加任何值。你需要将它添加到循环studentScores[count] = inputGrade;的部分中现在，您的do while循环应如下所示：

do
    {
        System.out.println("Please enter grade for averaging: ");
        int inputGrade = keyboard.nextInt();
        studentScores[count] = inputGrade;
        count++;
        gradesTotal += inputGrade;

    } while (count < numberOfGrades);

此外，在上一个for-loop内，您正在打印额外信息。只需从System.out.println

中删除该计数即可

 System.out.println("Grades entered were: " + studentScores[count]);

你不明白的任何事情让我知道谢谢

Answer 4

您忘记使用输入的花园填充数组

 do
    {
        System.out.println("Please enter grade for averaging: ");
        int inputGrade = keyboard.nextInt();
        studentScores[count]=inputGrade;
        count++;
        gradesTotal += inputGrade;

    } while (count < numberOfGrades);

java循环数组使用do ... while

4 个答案: