c# - 连接数组中匹配字符串的值

Question

我有一个字符串数组[2]，如下所示：

1st Array    2nd Aray
"100101"     "Testing123"
"100102"     "Apple123"
"100101"     "Dog123"
"100104"     "Cat123"
"100101"     "Animal123"

如果第一个数组中的元素匹配，我想连接第二个数组的所有元素。

例如，匹配的第一个数组的元素是“100101”、“100101”和“100101”。因此，具有相应第二个数组的连接值的字符串将如下所示：

"Testing123 Dog123 Animal123" 

如何优雅地实现这一点？

Answer 1

我是这样做的：

var results = 
    array1
        .Zip(array2, (x1, x2) => new { x1, x2 })
        .ToLookup(x => x.x1, x => x.x2)
        .Select(x => new { x.Key, Value = String.Join(" ", x), });

我得到了这个结果：

如果您需要以不同的方式提取结果，那么使用我的方法来获得您需要的结果并不难。

Answer 2

您可以使用GroupBy：

var strings = array1.Select((s,index) => new{ s, index })
    .GroupBy(x => x.s)
    .Select(g => 
        string.Join(" ", g.Select(x => array2.ElementAtOrDefault(x.index))));

foreach(string s in strings)
    Console.WriteLine(s);

如果您只想连接第一个数组中重复的字符串，请添加Where：

// ...
.GroupBy(x => x.s)
.Where(g => g.Count() > 1)
// ...

Here's a Demo

Answer 3

var indices = array1.Select((i, s) => new {Index = i, Str = s})
                                  .Where(e => e.Str == "100101")
                                  .Select(e => e.Index);
string result = string.Join(" ", array2.Select((i, s) => new {Index = i, Str = s})
                          .Where(e => indices.Contains(e.Index))
                          .Select(e => e.Str));

Answer 4

假设两个数组的长度相同，这应该会给你你需要的输出。

var array1 = new[] {"100101", "100102", "100101", "100104","100101" }; 

var array2 = new[] { "Testing123", "Apple123", "Dog123","Cat123", "Animal123" };

var result = new Dictionary<string, string>();
for (int i = 0; i < array1.Length; i++)
{
    // if the value has been found before
    if( result.ContainsKey( array1[i] ) ) {
        result[array1[i]] += " " + array2[i]; // append to existing "matched" entry
    }
    else {
        result.Add(array1[i], array2[i]); // add new unique value
    }
}

Answer 5

您可以压缩这两个数组，因为它们的大小相同。然后按第一个数组值对元素进行分组。然后加入元素。

我使用 linq 编写了一个示例程序

string[] array1 = new   string[]{"100101","100102","100101","100104","100101"};
            string[] array2 = new string[] { "Testing123", "Apple123", "Dog123", "Cat123", "Animal123" };

            var concatenatedString = array1.Zip(array2, (x, y) => new { First = x, Second = y }).GroupBy(t => t.First).Select(t=> string.Join(" ",t.Select(s=> s.Second))).ToList();

结果将包含连接字符串的列表。

希望能帮助到你

Answer 6

var arr1 = new [] { "100101", "100102", "100101", "100104", "100101" };
var arr2 = new [] { "Testing123", "Apple123", "Dog123", "Cat123", "Animal123" };

var result = string.Join(" ", arr2.Where((a, i) => i < arr1.Length && arr1[i] == "100101"));