java - 按长度过滤数组元素

Question

所以我希望能够要求用户输入数组的长度并用名称填充它。执行此操作后，程序将打印出名称及其旁边的字符串长度。

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

    // Read the number of kids
    System.out.print("How many kids are there? ");
    int size = sc.nextInt();

    // Read the names of the kids
    String [] kids = new String [size];

    for (int k = 0; k < kids.length; k++)
    {
        System.out.print("Enter name of kid #" + k + ": ");
        kids[k] = sc.next();
    }
    // Print all the names of the kids and the length of their names
    System.out.println("Names of kids with lengths are: ");

    for (int i = 0; i < kids.length; i++)
    {
      System.out.println(kids[i] + " " + kids[i].length());
    }

在此之后，我希望用户输入一个整数，程序将在数组中搜索该长度的任何字符串，如果找到任何字符串，我希望它打印出找到的所有字符串的首字母缩写。我必须使用这个程序的方法。但我似乎无法理解这个问题。

static int countByLength(String [] names, int length)
{
    int count = 0;



    return count;
}


/**
 * Filter an array of names and keep only those names with a given length
 * @param names: an array of names
 * @param length: an integer length
 * @return the array of names that have the given length
 */
static String [] filterByLength(String [] names, int length)
{
    String [] filtered = new String[length];

    for(int k = 0; k < filtered.length; k++)
    {
        filtered [k] = 
    }

    return filtered; 
}

}

Answer 1

一个问题是，您不知道会有多少结果，因此数组不是最好的数据结构。我建议使用列表，例如 ArrayList。然后您可以迭代该数组，将所有匹配的字符串添加到列表中。

static List<String> filterByLength(String [] names, int length)
{
   List<String> filtered = new ArrayList<String>();

   for(int k = 0; k < filtered.length; k++)
   {
       if (names.length() == length) filtered.add(names[k]);
   }

   return filtered; 
}