java - 如何打印带有空格的匹配数字的结果

Question

只是想到了一个简单的程序来练习java编码，但卡在了最后部分......

代码打印出所需的答案(与 5 号彩票的结果相比，输入的数字匹配哪些数字)，但打印的答案不带空格。我想也许可以在 += 时添加一个“”来matchingNumbers，但这没有做任何事情!

import java.util.Scanner;
import java.util.Arrays;
public class LottoChecker
{
    public static void main (String[] args)
    {
        Scanner in = new Scanner(System.in);
        int [] yourNumbers = new int [5];
        int yourInput, resultsInput;
        int [] results = new int [5];
        int currentNumber = 0;
        String matchingNumbers = "";
        for (int i=0; i<yourNumbers.length; i++)
        {
            System.out.println ("Enter your main numbers: " );
            yourInput = in.nextInt();
            yourNumbers[i]=yourInput;
        }

        for (int j=0; j<results.length; j++)
        {
            System.out.println("Enter the results from the main numbers: ");
            resultsInput = in.nextInt();
            results[j] = resultsInput;
        }

        System.out.println("Your Numbers: " + 
Arrays.toString(bubbleSort(yourNumbers)));
        System.out.println("The Results are: " + 
Arrays.toString(results));

        for (int i =0; i<yourNumbers.length;i++)
        {
            currentNumber = yourNumbers[i];
            for (int j=0;j<results.length;j++)
                if (currentNumber == results[j])

                    matchingNumbers += currentNumber + "";

        }

        System.out.println("Your matching numbers are: " + 
matchingNumbers);

    }

    public static int [] bubbleSort(int arr[]) 
    { 
        int n = arr.length; 
        for (int i = 0; i < n-1; i++) 
            for (int j = 0; j < n-i-1; j++) 
                if (arr[j] > arr[j+1]) 
                { 

                    int temp = arr[j]; 
                    arr[j] = arr[j+1]; 
                    arr[j+1] = temp; 
                } 
        return arr;
    } 

}

Answer 1

一个优雅的解决方案是使用 StringJoiner(" ")然后在每次迭代中添加数字。