Java：如何从第二种方法获取变量以在第三种方法中工作？

Posted 2023-01-09

家庭背景

我正在为我的课程编写一个Java程序，其中：

1. 生成一个介于1到100之间的10个随机数的数组

2. 应用程序会将数组传递给计算的平均值方法，然后将计算的平均值方法返回给主方法

3. 数组和数组中的平均值将传递到下面的方法中，在该方法中，将计算所有小于平均值的数字，并返回小于平均值的整数数并在main方法中显示。

这是我的初学者Java类，所以我对Java并不是最好的。我已经编程了大约一个半月。

TL; DR：我的问题是，我无法让第二种方法中的平均变量在第三种方法中工作以进行计算。

[在第三个方法中，我尝试调用另一个方法，例如：calcAverage(int [] array))和public static double countBelow (int[] array, calcAverage(array))

// main method
public static void main (String[] args)

    final int ARRAY_LENGTH = 10;

    //array object is created
    int array[] = new int [ARRAY_LENGTH];

    //for loop that loops through the array
    for (int rand = 0; rand < array.length; rand++)
    
        // random number generator from 1-100
        array[rand] = (int)(Math.random()*100);

    //end of loop

    //for loop that loops through the array
    for (int rand = 0; rand < array.length; rand++)
    
        // prints random numbers to the screen
        System.out.printf("Numbers: %d \n", array[rand]);

     //end of for loop


    //passing the array to the second method
    calcAverage(array);

    //prints out average
    System.out.print("Average is:");
    System.out.println (calcAverage(array));

    //passing array to the third method
     countBelow(calcAverage(array));


 // end of main method

    //declaring second method for calculating average
    public static double calcAverage(int[] array)
    

        //declaring variables for the sum and average
        double sum = 0;
        double average = 0;

        //for loop that loops through the array
        for (int rand = 0; rand < array.length; rand++)
        
            //computes the sum of the random numbers from first method
            sum += array[rand];
        

        //computes average
        average = (sum / array.length);

        //returns average to main method
        return average;


     //end of second method


    //start of third method
    public static int countBelow (int[] array, double average)
    
        int scoresBelow = 0;


        //for loop that loops through the array
        for (int rand = 0; rand < array.length; rand++)
        


            if (array[rand] < average)
            
                scoresBelow ++;
            

            else 

        

        return scoresBelow;


    



//end of class ArrayTest

我收到错误消息：

错误：ArrayTest类中的方法countBelow无法应用于给定类型；countBelow（calcAverage（array））;^必需：int []，double找到：双原因：实际和正式论点清单的长度不同1个错误

答案

[您要么需要在main方法中计算平均值，然后将其传递给countBelow，要么在countBelow中进行计算：

第一版-之前计算并传递给countBelow

// You pass the average already computed as a double argument:
public static double countBelow (int[] array, double average) 
    // Do what you must do...


// In the main method:
final int[] array = ...;
final double average = calcAverage(array);
countBelow(array, average);

第二版本 —直接在countBelow]中计算平均值

// You only pass the array:
public static double countBelow(int[] array) 
    // You compute the average here:
    final double average = calcAverage(array);

    // Do what you must do...


// In the main method:
final int[] array = ...;
countBelow(array);

另一答案

您需要在单独的步骤中执行此操作

另一答案

您的countBelow方法似乎有两个参数：int[] array和calcAverage(array)的结果，因此签名应为：