java - 使用扫描器的多维数组

Question

package practice;

import java.util.*;
import java.util.ArrayList;
import java.util.Iterator;

public class Practice {

public static void main(String[] args){

    Scanner input = new Scanner(System.in);
    StringBuilder output = new StringBuilder();


    System.out.println("Enter the number of rows & columns: ");

    System.out.print("Enter the number of rows: ");
    int row = input.nextInt();
    System.out.print("Enter the number of columns: ");
    int columns = input.nextInt();

    int [][]nums = new int[row][columns];

    for (int i = 0; i < row; i++)
    {
        for (int j = 0; j < columns; j++)
        {
            System.out.print("Number " + (j + 1) + ": ");
            nums[i][j] = input.nextInt();
            output.append("\n").append(nums[i][j]);
        }
        System.out.println( " " );

    }

    System.out.println(output);

   }

}

我上面的代码有问题，我正在练习多维数组。我想要的是制作一个由行和列分隔的数字列表，示例:如果我在行中输入 3，在列中输入 4，则输出数字应该像这样排列。

10 20 30 40
50 60 70 80
90 100 101 102

但问题是输出显示的是一长串连续数字。 谁能帮我解决这个问题，

谢谢，

Answer 1

切换到下一行时，您必须在输出中添加新行:

public static void main(String[] args) {

    Scanner input = new Scanner(System.in);
    StringBuilder output = new StringBuilder();


    System.out.println("Enter the number of rows & columns: ");

    System.out.print("Enter the number of rows: ");
    int row = input.nextInt();
    System.out.print("Enter the number of columns: ");
    int columns = input.nextInt();

    int[][] nums = new int[row][columns];

    for (int i = 0; i < row; i++) {
        for (int j = 0; j < columns; j++) {
            System.out.print("Number " + (j + 1) + ": ");
            nums[i][j] = input.nextInt();
            output.append(" ").append(nums[i][j]);
        }
        output.append("\n");
        System.out.println("\n");

    }

    System.out.println(output);

}