How to get last lower case characters as a string from string in C#

This wil do:

string input = "FrCABisch";
string trail = String.Empty;

foreach (var character in input)
{
	string check = character.ToString();
	if (character.ToString().Equals(character.ToString().ToUpper()))
	{
		trail = string.Empty;
	}
	else
	{
		trail += character;
	}
}

Console.WriteLine(trail);

// trail -> isch

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Hi,

What're the criteria for getting these specific substrings?

I would just do a regular expression:

string lastLowercaseChars = String.Empty;
var re = new Regex("[a-z]+$");
var match = re.Match("FrCABisch");
if(match.Success)
{
  lastLowercaseChars = match.Value;
}

// lastLowercaseChars has your final result

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Gustav's method should work, too, but is very inefficient (building and truncating strings multiple times, many character to string conversions). It could be improved greatly by making one pass through the string in reverse order to find the last position of an uppercase character and then do a substring based on that result. The pseudo-code:

int posLastUpper = 0:
for(int i = input.Length - 1; i >= 0; i--)
{
  char c = input[i];
  if(c.IsUpper())
  {
    posLastUpper = i;
    break;
  }
}
string lastLowercaseChars = input.Substring(posLastUpper);

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Might require some tweaking (e.g. if posLastUpper is 0 then just return the original string) but that idea should work a little more efficiently.

Hi,
Sorry, I was not paying attention to the question title.
RegEx is the easiest way, indeed. Some sample code:
List<string> list = new List<string>();
   list.Add("FRCABisch");
   list.Add("FrCABisch");
   list.Add("YTkumoty");

   string pattern = @"([a-z][^A-Z])\w+";
   Regex regex = new Regex(pattern);
   List<string> result = new List<string>();

   foreach (string val in list)
   {
       Match match = regex.Match(val);
       result.Add(match.Value);
   }
   
   Console.Write(result);

Hi Eduard and gr8gonzo,

It works great for examples and just realized it's not work if such a case: ptrain.FrCABisch is it possible start reading from right to left ?

Hi Hakan;

The following code snippet should do what you want.

var pattern = "^.+?([a-z]+)$";
List<string> input = new List<string>() {"FRCABisch", "FrCABisch", "YTkumoty"};

foreach (string str in input)
{
    Console.WriteLine("Input string = {0} and the ending is = {1}", str, Regex.Match(str, pattern).Groups[1].Value);   
}

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The results will be

Input string = FRCABisch and the ending is = isch
Input string = FrCABisch and the ending is = isch
Input string = YTkumoty and the ending is = kumoty

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Hi gr8gonzo,

You're right working extremely good. Thank you.