java - 使用方法填充二维数组时如何修复Array Errors和ArrayStoreException

Question

我在下面粘贴了我的代码。
数组确实为我提供了随机数，但是在数组末尾会 pop 错误，并且我无法修复错误。
目标是产生一个具有2列和n个行的数组。随机整数将填充数组。
我有一个主控件，在其中创建了一个二维数组来保存值，并且我使用Array.fill()方法调用了我制作的randArray方法，该方法使用随机整数构造了实际的数组。

问题是一旦代码运行，它给了我一些我无法摆脱的错误。这些是错误:

Exception in thread "main" java.lang.ArrayStoreException: [[I
at java.base/java.util.Arrays.fill(Arrays.java:3639)
at Animal.main(Animal.java:22)

我尝试过的事情:

将范围更改为range-1

将行更改为第1行

在第二个方法

中更改i和j值

将我的教科书扔进它所属的垃圾中

我应该朝哪个方向前进？任何帮助将非常感激。

import java.util.Scanner;
import java.util.Arrays;
import java.util.Random; //import library for generating random numbers

//Creating an array with 2 columns, the number of rows are based on user input and the numbers
//inside the array are randomized between 0 and x with user giving x

public class Animal {

    public static void main(String [] args)
    {
        Scanner input = new Scanner(System.in);

        System.out.println("Enter the number of rows: ");
        int numNodes = input.nextInt();    //this will be the number of rows in the array

        System.out.println("Enter the maximum:  ");
        double max = input.nextDouble();    //array data is inside this range 


        int[][] something = new int [numNodes][];
        Arrays.fill(something, randArray(numNodes,max));



  //    System.out.println("The rows are: " + arrayMade(numNodes,networkSize)); //testing the array to see if it works

       System.out.println(something);
    }

/** Creating an array to fill the random array with random ints
 * 
 * @param numRows the number of rows the array will have
 * @param range the maximum for a value in the array
 * @return randArray returns a randomized filled in 2-d array
 */

public static int[][] randArray (int numRows, double range)    //method to make the array 
    { 
        int[][] randArray = new int[numRows+1][2];                         
        Random rand = new Random(); 

        int count = numRows-1;
        int i = 0;

     while(i < count){  //this loops based on how many rows there are

        for (int j = 0; j < 1; j++)
        {
            randArray[i][0] = rand.nextInt((int)range) ;  // random integer from 0 to max
            randArray[i][1] = rand.nextInt((int)range) ;

        System.out.println(randArray[i][0] + "   " + randArray[i][1]); //test line
        i++;

        }//end for-loop


      }//end while-loop

        return randArray;
    }//end arrayMade


}//end class

Answer 1

您不必使用Arrays.fill，只需将randArray函数的返回值分配给2d数组。

int[][] something = randArray(numNodes, max);

PS:您需要一种将2d数组打印到控制台的方法，使用 System.out.println(something)将输出意外结果。

另外，删除 for (int j = 0; j < 1; j++)循环，这确实是不必要的。

这是您可以引用的最终代码:

import java.util.Random;
import java.util.Scanner;

//Creating an array with 2 columns, the number of rows are based on user input and the numbers
//inside the array are randomized between 0 and x with user giving x

public class Animal {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        System.out.println("Enter the number of rows: ");
        int numNodes = input.nextInt();    //this will be the number of rows in the array

        System.out.println("Enter the maximum:  ");
        int max = input.nextInt();    //array data is inside this range


        int[][] something = randArray(numNodes, max);


        //    System.out.println("The rows are: " + arrayMade(numNodes,networkSize)); //testing the array to see if it works

        System.out.println(something);
    }

    /**
     * Creating an array to fill the random array with random ints
     *
     * @param numRows the number of rows the array will have
     * @param range   the maximum for a value in the array
     * @return randArray returns a randomized filled in 2-d array
     */

    public static int[][] randArray(int numRows, int range)    //method to make the array
    {
        int[][] randArray = new int[numRows + 1][2];
        Random rand = new Random();

        int count = numRows - 1;
        int i = 0;

        while (i < count) {  //this loops based on how many rows there are

            randArray[i][0] = rand.nextInt(range);  // random integer from 0 to max
            randArray[i][1] = rand.nextInt(range);

            System.out.println(randArray[i][0] + "   " + randArray[i][1]); //test line
            i++;

        }//end while-loop

        return randArray;
    }//end arrayMade


}//end class