Question

当我运行我的程序并选择0到100之间的数字时，它会错误地打印我的答案。

Java控制台

 ----jGRASP exec: java TestScores

How many tests do you have? 3
Enter grade for Test 1: 80
Enter grade for Test 2: 80
Enter grade for Test 3: 80
The average is: 26.666666666666668The average is: 53.333333333333336The average is: 80.0
 ----jGRASP: operation complete.

import java.util.Scanner;

public class TestScores {

    public static void main(String[] args)
    {
        int numTests = 0;
        double[] grade = new double[numTests];
        double totGrades = 0;
        double average;
        int check = 1;

        Scanner keyboard = new Scanner(System.in);
        System.out.print("How many tests do you have? ");
        numTests = keyboard.nextInt();
        grade = new double[(int) numTests];

        for (int index = 0; index < grade.length; index++)
        {
            System.out.print("Enter grade for Test " + (index + 1) + ": ");
            grade[index] = keyboard.nextDouble();

            if (grade[index] < 0 || grade[index] > 100)
            {
                try
                {
                    throw new InvalidTestScore();
                } 
                catch (InvalidTestScore e)
                {
                    e.printStackTrace();
                }
                break;
            }
        }

        for (int index = 0; index < grade.length; index++) {
            totGrades += grade[index];
            average = totGrades / grade.length;
            System.out.print("The average is: " + average);
        }
    }
}

public class InvalidTestScore extends Exception 
{
    public InvalidTestScore() 
    {
        super(" Error: Enter a number between 0 and 100");
    }
}

Answer 1

您可以在循环内打印计算平均值的平均值。

仅在循环外打印。

Answer 2

你应该在循环中计算sum，然后（在循环之后）除以元素的数量。

Answer 3

我将从循环内部计算总和的语句移动到外部，这是有效的。

我的新代码是。

import java.util.Scanner;

公共类TestScores

{

    public static void main(String[]args)

    {

            int numTests = 0;

            double[] grade = new double[numTests];

            double totGrades = 0;

            double average;

                 int check = 1;


            Scanner keyboard = new Scanner(System.in);


            System.out.print("How many tests do you have? ");

            numTests = keyboard.nextInt();



            grade = new double[(int) numTests];



            for (int index = 0; index < grade.length; index++)

            {

                    System.out.print("Enter grade for Test " + (index + 1) + ": ");

                    grade[index] = keyboard.nextDouble();


                    if (grade[index] < 0 || grade[index]> 100)

                    {
                                    try 

                                      {

                                throw new InvalidTestScore();


                            }

                                       catch (InvalidTestScore e) 

                            {

                                    e.printStackTrace();

                            }
                                        break;

                    }

            }

                for (int index = 0; index < grade.length; index++)
                 {  
                        totGrades += grade[index];



              }

                  average = totGrades/grade.length;


                  System.out.print("The average is: " + average);

    }

}

公共类InvalidTestScore扩展了Exception { public InvalidTestScore（） { super（“错误：输入0到100之间的数字”）; } }

你可以关闭我的帖子。

我的程序打印声明是错误的

3 个答案: