解析一个字符串数组以检查一个值有多少次

Question

Say I have this array of strings:

string[] arrayToParse = {2, G, R, G, B};

I need to parse through the array to check how many times is a string present so that I may end up with values like this:

2
GG
R
B

So each time the loop detects if there's another string identical, he "concatenates", then add the value to a list.

If I take another example: string[] arrayToParse2 = {2, Q, T, T, U, U} Should end up with these values:

2
Q
TT
UU

Any help anyone?

Answer 1

Use LINQ ( GroupBy method) and string.Join :

string[] arrayToParse = {"2", "G", "R", "G", "B"};

string[] results = arrayToParse.GroupBy(x => x)
                               .Select(g => string.Join(string.Empty, g))
                               .ToArray();

Works for both your sample inputs.

Answer 2

You can use Linq:

var stringGroups = arrayToParse.GroupBy(str => str);

Now you can display these groups with String.Join :

foreach(var group in stringGroups)
    Console.WriteLine(string.Join("", group));

Answer 3

I would go with the LINQ approach. If it is not available or you don't want to use it, here is a longuer version (easier to understand if you've never used LINQ).

string[] arrayToParse = {2, G, R, G, B};
List<String> parsedList = new List<String>

foreach(String sToParse in arrayToParse)
{
  if (parsedList.Count <= 0)
     parsedList.Add(sToParse);

  else
  foreach(String sInParsedList in parsedList)
  {
     if(sToParse == sInParsedList)
        sInParsedList += sToParse;

     else
     parsedList.Add(sToParse);
  }

 string[] parsedArray = parsedList.ToArray();