java - 编写方法来测试java中的平均成绩

Question

我正在为家庭作业编写代码，但遇到了困难。

作业是编写一个程序来获取用户输入的 10 个成绩的平均值。

我相信我得到了大部分，但是在 averageGrades 方法中，当我尝试声明 average 时，它不会让我这样做。

这是我的:

public class Averagegrades 
{
    public int min, max;
    double average; 

    public static void main (String [] args)
    {

        double sum = 0;
        Scanner scan = new Scanner(System.in);
        int [] gradesarray = new int[10];

        System.out.println("Please enter the 10 test grades: ");

        for (int i = 0; i < gradesarray.length; i++)
        {            
            gradesarray[i] = scan.nextInt();

            if(gradesarray[i] > 100)
            {
                System.out.println("Please enter a number within 0 - 100: ");
                gradesarray[i] = scan.nextInt();
            }
        }

        System.out.println("These are the grades you entered: " +
            Arrays.toString(gradesarray));
        System.out.println("You have entered " + gradesarray.length + " grades");

        for(double num : gradesarray)
        {
            sum = sum + num;
        }

        System.out.println("This is the sum " + sum);
    }

    public double averageGrades()
    {
        average = sum / (double) gradesarray.length;
    }

Answer 1

所以这会让你声明平均。问题是方法 averageGrades 找不到 sum 或 gradesarray，因为这两个变量是在 main 方法中声明的，因此对方法不可见。

package test;

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

public class Averagegrades 
{
public int min, max;
double average; 
static double sum;
static int[] gradesarray;

public static void main (String [] args)
{
    sum = 0;
    Scanner scan = new Scanner(System.in);
    gradesarray = new int[10];
    System.out.println("Please enter the 10 test grades: ");

    for (int i = 0; i < gradesarray.length; i++)
    {            
        gradesarray[i] = scan.nextInt();
        if(gradesarray[i] > 100)
        {
            System.out.println("Please enter a number within 0 - 100: ");
            gradesarray[i] = scan.nextInt();
        }
    }
    System.out.println("These are the grades you entered: "+
            Arrays.toString(gradesarray));
    System.out.println("You have entered "+gradesarray.length+" grades");

    for(double num : gradesarray)
    {
        sum = sum + num;
    }
    System.out.println("This is the sum "+sum);
}

public double averageGrades()
{
    average = sum / (double) gradesarray.length;
    return average ;
}

或者你也可以做...

public double averageGrades(int sum, int[] gradesarray)
{
  average = sum / (double) gradesarray.length; 
  return average ;
}

然后在调用方法时...

averageGrades(sum, gradesarray);

通过这样做，您不必将 sum 和 gradesarray 声明移到 main 方法之外。

希望这对您有所帮助!