如何比较两个字符串数组，并找到公共字符串数组的索引号并将其应用于第三个字符串数组？

Question

我有三个字符串数组

string[] stringArray= {"AAA", "BBB", "CCC","DDD", "EEE","FFF","GGG","HHH" };
string[] stringArray1 = { "A", "B", "C","D", "E","F","G","H" };
string[] stringArray2 = { "BBB", "DDD","FFF","HHH" };

我该如何比较 stringArray2 和 stringArray 并找到与 stringArray 匹配的索引号。 找到索引号后，我需要将其应用于 stringArray1 并显示结果。

我尝试了以下代码，但未能获取匹配字符串。

int j=0;
string line = null;
List<string> finalstring = new List<string>();

for (int i = 0; i < stringArray.Count; i++)
{ 
   while(stringArray[i] == stringArray2[j])
   {
      line = stringArray2[i];
      finalstring.Add(line);
      j++;
   }
}

- TechBrkTru

---

你期望的最终结果是什么？ - sujith karivelil

finalstring as = {"B", "D", "F", "H"} - TechBrkTru

Answer 1

我认为你必须像这样尝试：

var result = stringArray1.Where(c => // iterating stringArray1
             stringArray2.Where(x => stringArray.Contains(x)) // filtering stringArray2 elements
                         .Any(y=>y.Contains(c))).ToList(); // collect the final result

这是一个工作示例，供您参考

- sujith karivelil

Answer 2

int j=0;
string line = null;
List<string> finalstring = new List<string>();
for (int i = 0; i < stringArray.Length; i++)
//for (int i = 0; i < stringArray.Count; i++)   // <-- Count is not proper way to get total elements in an array
{
   j = 0;  // <-- you failed to reinitialize 'j' 
   //while(stringArray[i] == stringArray2[j])  // <-- while is not proper way to compare
   if(stringArray[i] == stringArray2[j])
   {
      //line = stringArray2[i];

      //if only first charracter is needed
      finalstring.Add(new string(stringArray2[i][0], 1));

      //if complete string is needed
      //finalstring.Add(stringArray2[i]);

      j++;
   }
}

上述方法并非最优的比较方式。您可以尝试使用HashSet类。

    string[] stringArray= {"AAA", "BBB", "CCC","DDD", "EEE","FFF","GGG","HHH" };
    string[] stringArray1 = { "A", "B", "C","D", "E","F","G","H" };
    string[] stringArray2 = { "BBB", "DDD","FFF","HHH" };

    //convert string array to hashset
    var hashSet = new HashSet<string>(stringArray);

    int j=0;
    string line = null;
    List<string> finalstring = new List<string>();

    for (int i = 0; i < stringArray2.Length; i++)
    {
        if(hashSet.Contains(stringArray2[i]))
        {
            //if only first charracter is needed
            finalstring.Add(new string(stringArray2[i][0], 1));
        }
    } 

- sameerkn

Answer 3

List<string> finalList = new List<string>();
stringArray.Select((value,index) => new { value, index })
.Where(num => stringArray2.Contains(num.value)).ToList()
.ForEach(num => finalList.Add(stringArray1[num.index]));

- Tyress

Answer 4

您正在尝试比较相同索引上的元素，但是您必须在stringArray中搜索stringArray2的元素。您可以使用Array.IndexOf在数组中查找所需的元素。

string[] stringArray= {"AAA", "BBB", "CCC","DDD", "EEE","FFF","GGG","HHH" };
string[] stringArray1 = { "A", "B", "C","D", "E","F","G","H" };
string[] stringArray2 = { "BBB", "DDD","FFF","HHH" };
    int j=0;
string line = null;
List<string> finalstring = new List<string>();

for (int i = 0; i < stringArray2.Count(); i++)
{ 
   if(Array.IndexOf(stringArray, stringArray2[i]) != -1)
   {
      int idx = Array.IndexOf(stringArray1, stringArray2[i][0].ToString());
      if(idx!=-1)
        finalstring.Add(stringArray1[idx]);
    }  
}

使用Linq进行编辑

var result2 = stringArray1.Where(c=>
              stringArray2.Intersect(stringArray)
              .Any(i=>i.Contains(c)));

- Adil

Answer 5

你可以通过使用 Linq 选择索引来实现（where >= 0 过滤掉所有不匹配的项）：

string[] stringArray = { "AAA", "BBB", "CCC", "DDD", "EEE", "FFF", "GGG", "HHH" };
string[] stringArray1 = { "A", "B", "C", "D", "E", "F", "G", "H" };
string[] stringArray2 = { "BBB", "DDD", "FFF", "HHH" };

var matches = stringArray2
    .Select(s => Array.FindIndex(stringArray, s2 => s2 == s))
    .Where(i => i >= 0).Select(i => stringArray1[i])
    .ToList();

这里有一个dotnetfiddle

- Nico