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find string using c#?

I am trying find a string in below string.
http://example.com/TIGS/SIM/Lists/Team Discussion/DispForm.aspx?ID=1779
by using http://example.com/TIGS/SIM/Lists string. How can I get Team Discussion word from it?
Some times strings will be
http://example.com/TIGS/SIM/Lists/Team Discussion/DispForm.aspx?ID=1779
I need `Team Discussion`
http://example.com/TIGS/ALIF/Lists/Artifical Lift Discussion Forum 2/DispForm.aspx?ID=8
I need `Artifical Lift Discussion Forum 2`

If you're always following that pattern, I recommend #Justin's answer. However, if you want a more robust method, you can always couple the System.Uri and Path.GetDirectoryName methods, then perform a String.Split. Like this example:
String url = #"http://example.com/TIGS/SIM/Lists/Team Discussion/DispForm.aspx?ID=1779";
System.Uri uri = new System.Uri(url);
String dir = Path.GetDirectoryName(uri.AbsolutePath);
String[] parts = dir.Split(new[]{ Path.DirectorySeparatorChar });
Console.WriteLine(parts[parts.Length - 1]);
The only major problem, however, is you're going to wind up with a path that's been "encoded" (i.e. your space is now going to be represented by a %20)

This solution will get you the last directory of your URL regardless of how many directories are in your URL.
string[] arr = s.Split('/');
string lastPart = arr[arr.Length - 2];
You could combine this solution into one line, however it would require splitting the string twice, once for the values, the second for the length.

If you wanted to see a regular expression example:
string input = "http://example.com/TIGS/SIM/Lists/Team Discussion/DispForm.aspx?ID=1779";
string given = "http://example.com/TIGS/SIM/Lists";
System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(given + #"\/(.+)\/");
System.Text.RegularExpressions.Match match = regex.Match(input);
Console.WriteLine(match.Groups[1]); // Team Discussion

Here's a simple approach, assuming that your URL always has the same number of slashes before the are you want:
var value = url.Split(new[]{'/'}, StringSplitOptions.RemoveEmptyEntries)[5];

Here is another solution that provides the following advantages:
Does not require the use of regular expressions.
Does not require a certain 'count' of slashes be present (indexing based of a specific number). I consider this a key benefit because it makes the code less likely to fail if some part of the URL changes. Ultimately it is best to base your parsing logic off which part of the text's structure you consider least likely to change.
This method, however, DOES rely on the following assumptions, which I consider to be the least likely to change:
URL must have "/Lists/" right before target text.
URL must have "/" right after target text.
Basically, I just split the string twice, using text that I expect to be surrounding the area I am interested in.
String urlToSearch = "http://example.com/TIGS/SIM/Lists/Team Discussion/DispForm.aspx";
String result = "";
// First, get everthing after "/Lists/"
string[] temp1 = urlToSearch.Split(new String[] { "/Lists/" }, StringSplitOptions.RemoveEmptyEntries);
if (temp1.Length > 1)
{
// Next, get everything before the first "/"
string[] temp2 = temp1[1].Split(new String[] { "/" }, StringSplitOptions.RemoveEmptyEntries);
result = temp2[0];
}
Your answer will then be stored in the 'result' variable.

C# how to split a string backwards?

What i'm trying to do is split a string backwards. Meaning right to left.
string startingString = "<span class=\"address\">Hoopeston,, IL 60942</span><br>"
What I would do normally is this.
string[] splitStarting = startingString.Split('>');
so my splitStarting[1] would = "Hoopeston,, IL 60942</span"
then I would do
string[] splitAgain = splitStarting[1].Split('<');
so splitAgain[0] would = "Hoopeston,, IL 60942"
Now this is what I want to do, I want to split by ' ' (a space) reversed for the last 2 instances of ' '.
For example my array would come back like so:
[0]="60942"
[1]="IL"
[2] = "Hoopeston,,"
To make this even harder I only ever want the first two reverse splits, so normally I would do something like this
string[] splitCity,Zip = splitAgain[0].Split(new char[] { ' ' }, 3);
but how would you do that backwards? The reason for that is, is because it could be a two name city so an extra ' ' would break the city name.

Regular expression with named groups to make things so much simpler. No need to reverse strings. Just pluck out what you want.
var pattern = #">(?<city>.*) (?<state>.*) (?<zip>.*?)<";
var expression = new Regex(pattern);
Match m = expression .Match(startingString);
if(m.success){
Console.WriteLine("Zip: " + m.Groups["zip"].Value);
Console.WriteLine("State: " + m.Groups["state"].Value);
Console.WriteLine("City: " + m.Groups["city"].Value);
}
Should give the following results:
Found 1 match:
1. >Las Vegas,, IL 60942< has 3 groups:
1. Las Vegas,, (city)
2. IL (state)
3. 60942 (zip)
String literals for use in programs:
C#
#">(?<city>.*) (?<state>.*) (?<zip>.*?)<"

One possible solution - not optimal but easy to code - is to reverse the string, then to split that string using the "normal" function, then to reverse each of the individual split parts.
Another possible solution is to use regular expressions instead.

I think you should do it like this:
var s = splitAgain[0];
var zipCodeStart = s.LastIndexOf(' ');
var zipCode = s.Substring(zipCodeStart + 1);
s = s.Substring(0, zipCodeStart);
var stateStart = s.LastIndexOf(' ');
var state = s.Substring(stateStart + 1);
var city = s.Substring(0, stateStart );
var result = new [] {zipCode, state, city};
Result will contain what you requested.

If Split could do everything there would be so many overloads that it would become confusing.
Don't use split, just custom code it with substrings and lastIndexOf.
string str = "Hoopeston,, IL 60942";
string[] parts = new string[3];
int place = str.LastIndexOf(' ');
parts[0] = str.Substring(place+1);
int place2 = str.LastIndexOf(' ',place-1);
parts[1] = str.Substring(place2 + 1, place - place2 -1);
parts[2] = str.Substring(0, place2);

You can use a regular expression to get the three parts of the string inside the tag, and use LINQ extensions to get the strings in the right order.
Example:
string startingString = "<span class=\"address\">East St Louis,, IL 60942</span><br>";
string[] city =
Regex.Match(startingString, #"^.+>(.+) (\S+) (\S+?)<.+$")
.Groups.Cast<Group>().Skip(1)
.Select(g => g.Value)
.Reverse().ToArray();
Console.WriteLine(city[0]);
Console.WriteLine(city[1]);
Console.WriteLine(city[2]);
Output:
60942
IL
East St Louis,,

How about
using System.Linq
...
splitAgain[0].Split(' ').Reverse().ToArray()
-edit-
ok missed the last part about multi word cites, you can still use linq though:
splitAgain[0].Split(' ').Reverse().Take(2).ToArray()
would get you the
[0]="60942"
[1]="IL"
The city would not be included here though, you could still do the whole thing in one statement but it would be a little messy:
var elements = splitAgain[0].Split(' ');
var result = elements
.Reverse()
.Take(2)
.Concat( new[ ] { String.Join( " " , elements.Take( elements.Length - 2 ).ToArray( ) ) } )
.ToArray();
So we're
Splitting the string,
Reversing it,
Taking the two first elements (the last two originally)
Then we make a new array with a single string element, and make that string from the original array of elements minus the last 2 elements (Zip and postal code)
As i said, a litle messy, but it will get you the array you want. if you dont need it to be an array of that format you could obviously simplfy the above code a little bit.
you could also do:
var result = new[ ]{
elements[elements.Length - 1], //last element
elements[elements.Length - 2], //second to last
String.Join( " " , elements.Take( elements.Length - 2 ).ToArray( ) ) //rebuild original string - 2 last elements
};

At first I thought you should use Array.Reverse() method, but I see now that it is the splitting on the ' ' (space) that is the issue.
Your first value could have a space in it (ie "New York"), so you dont want to split on spaces.
If you know the string is only ever going to have 3 values in it, then you could use String.LastIndexOf(" ") and then use String.SubString() to trim that off and then do the same again to find the middle value and then you will be left with the first value, with or without spaces.

Was facing similar issue with audio FileName conventions.
Followed this way: String to Array conversion, reverse and split, and reverse each part back to normal.
char[] addressInCharArray = fullAddress.ToCharArray();
Array.Reverse(addressInCharArray);
string[] parts = (new string(addressInCharArray)).Split(new char[] { ' ' }, 3);
string[] subAddress = new string[parts.Length];
int j = 0;
foreach (string part in parts)
{
addressInCharArray = part.ToCharArray();
Array.Reverse(addressInCharArray);
subAddress[j++] = new string(addressInCharArray);
}

C# Regex.Split: Removing empty results

I am working on an application which imports thousands of lines where every line has a format like this:
|* 9070183020 |04.02.2011 |107222 |M/S SUNNY MEDICOS |GHAZIABAD | 32,768.00 |
I am using the following Regex to split the lines to the data I need:
Regex lineSplitter = new Regex(#"(?:^\|\*|\|)\s*(.*?)\s+(?=\|)");
string[] columns = lineSplitter.Split(data);
foreach (string c in columns)
Console.Write("[" + c + "] ");
This is giving me the following result:
[] [9070183020] [] [04.02.2011] [] [107222] [] [M/S SUNNY MEDICOS] [] [GHAZIABAD] [] [32,768.00] [|]
Now I have two questions.
1. How do I remove the empty results. I know I can use:
string[] columns = lineSplitter.Split(data).Where(s => !string.IsNullOrEmpty(s)).ToArray();
but is there any built in method to remove the empty results?
2. How can I remove the last pipe?
Thanks for any help.
Regards,
Yogesh.
EDIT:
I think my question was a little misunderstood. It was never about how I can do it. It was only about how can I do it by changing the Regex in the above code.
I know that I can do it in many ways. I have already done it with the code mentioned above with a Where clause and with an alternate way which is also (more than two times) faster:
Regex regex = new Regex(#"(^\|\*\s*)|(\s*\|\s*)");
data = regex.Replace(data, "|");
string[] columns = data.Split(new[] { '|' }, StringSplitOptions.RemoveEmptyEntries);
Secondly, as a test case, my system can parse 92k+ such lines in less than 1.5 seconds in the original method and in less than 700 milliseconds in the second method, where I will never find more than a couple of thousand in real cases, so I don't think I need to think about the speed here. In my opinion thinking about speed in this case is Premature optimization.
I have found the answer to my first question: it cannot be done with Split as there is no such option built in.
Still looking for answer to my second question.

Regex lineSplitter = new Regex(#"[\s*\*]*\|[\s*\*]*");
var columns = lineSplitter.Split(data).Where(s => s != String.Empty);
or you could simply do:
string[] columns = data.Split(new char[] {'|'}, StringSplitOptions.RemoveEmptyEntries);
foreach (string c in columns) this.textBox1.Text += "[" + c.Trim(' ', '*') + "] " + "\r\n";
And no, there is no option to remove empty entries for RegEx.Split as is for String.Split.
You can also use matches.

I think this may work as an equivalent to remove empty strings:
string[] splitter = Regex.Split(textvalue,#"\s").Where(s => s != String.Empty).ToArray<string>();

Don't use a regex at all in your case.
It doesn't seem you need one and regexes are much slower (and have a much higher overhead) than directly using the string functions.
So use somewhat like:
const Char[] splitChars = new Char[] {'|'};
string[] splitData = data.Split(splitChars, StringSplitOptions.RemoveEmptyEntries)

As an alternative to splitting, which is always going to cause trouble when your delimiters are also present at the beginning and end of the input, you can try matching the contents within the pipes:
foreach (var token in Regex.Matches(input, #"\|\*?\s*(\S[^|]*?)\s*(?=\|)"))
{
Console.WriteLine("[{0}]", token.Groups[1].Value);
}
// Prints the following:
// [9070183020]
// [04.02.2011]
// [107222]
// [M/S SUNNY MEDICOS]
// [GHAZIABAD]
// [32,768.00]

I might have the wrong idea here, but you just want to split the data string using the '|' character as a delimiter? In that case you couldtry:
string[] result = data.Split(new[] { "|" }, StringSplitOptions.RemoveEmptyEntries).Select(d => d.Trim()).ToArray();
This will return all the fields, without spaces and with empty fields removed. You can what you like in the Select part to format the results e.g.
.Select(d => "[" + d.Trim() + "]").ToArray();

Based on #Jaroslav Jandek's great answer, I wrote an extension method, I put that here, maybe it can save your time.
/// <summary>
/// String.Split with RemoveEmptyEntries option for clean up empty entries from result
/// </summary>
/// <param name="s">Value to parse</param>
/// <param name="separator">The separator</param>
/// <param name="index">Hint: pass -1 to get Last item</param>
/// <param name="wholeResult">Get array of split value</param>
/// <returns></returns>
public static object CleanSplit(this string s, char separator, int index, bool wholeResult = false)
{
if (string.IsNullOrWhiteSpace(s)) return "";
var split = s.Split(new char[] { separator }, StringSplitOptions.RemoveEmptyEntries);
if (wholeResult) return split;
if (index == -1) return split.Last();
if (split[index] != null) return split[index];
return "";
}

1. How do I remove the empty results?
You can use LINQ to remove all entries that are equal to string.Empty :
string[] columns = lineSplitter.Split(data);
columns = columns.ToList().RemoveAll(c => c.Equals(string.Empty)).ToArray();
2. How can I remove the last pipe?
You can use LINQ here to remove all the entries equal to the character you want to remove :
columns = columns.ToList().RemoveAll(c => c.Equals("|")).ToArray();

How about this:
assuming we have a line:
line1="|* 9070183020 |04.02.2011 |107222 |M/S SUNNY MEDICOS |GHAZIABAD | 32,768.00 |";
we can have required result as:
string[] columns =Regex.Split(line1,"|");
foreach (string c in columns)
c=c.Replace("*","").Trim();
This will give following result:
[9070183020] [04.02.2011] [107222] [M/S SUNNY MEDICOS] [GHAZIABAD] [32,768.00]

use this solution:
string stringwithDelemeterNoEmptyValues= string.Join(",", stringwithDelemeterWithEmptyValues.Split(",".ToCharArray(), StringSplitOptions.RemoveEmptyEntries));

Converting String List to Single Quoted List in C# .NET

I have list of strings. I want to convert each element of it to single quoted string (i.e "ABC" --> 'ABC'), How to do this in .net.
Thanks,
Omkar

Linq can help here.
var newList = oldList.Select(c => c.Replace("\"", "'"));

This is already well answered. However, I have the hunch that you are taking a list of strings in C#, then trying to build an SQL expression for use in IN statements, e.g.:
SELECT * FROM table WHERE name IN ('John','Mary','Peter')
In that case, you'd need to join the strings together, as well as protect from code injection attacks by doubling any single-quote characters.
StringBuilder sb = new StringBuilder();
foreach (string entry in list) {
if (sb.Length > 0) sb.Append(",");
sb.Append("\'" + entry.Replace("'","''") + "\'");
}
string expr = sb.ToString();
You'd also need to handle the special case when the list is empty because IN () is not a valid syntax for SQL.
If this is not what you want, just ignore me. :-)

I assume you have regular strings s to 's' (quoted string) and you wanted a List<> to be converted.
List<string> stringList = new List<string>();
//Fill the list with strings here.
var query = from str in stringList
select string.Format("\'{0}\'", str);
List<string> quotedList = query.ToList<string>();

If you want to replace all double with single quotes, simply do this:
myString = myString.Replace( "\"", "'" );
However, note that ' is not a valid string delimiter in C#, so you can't have the string 'ABC', but you can have the string "'ABC'" that contains the text 'ABC'
EDIT
When looking at Geoff's answer, I saw that you wanted a list. In that case, his answer is almost correct- Try this variant instead:
var convertedList = myStringList.Select(s => s = s.Replace("\"", "'").ToList();

How to split a string while preserving line endings?

I have a block of text and I want to get its lines without losing the \r and \n at the end. Right now, I have the following (suboptimal code):
string[] lines = tbIn.Text.Split('\n')
.Select(t => t.Replace("\r", "\r\n")).ToArray();
So I'm wondering - is there a better way to do it?
Accepted answer
string[] lines = Regex.Split(tbIn.Text, #"(?<=\r\n)(?!$)");

The following seems to do the job:
string[] lines = Regex.Split(tbIn.Text, #"(?<=\r\n)(?!$)");
(?<=\r\n) uses 'positive lookbehind' to match after \r\n without consuming it.
(?!$) uses negative lookahead to prevent matching at the end of the input and so avoids a final line that is just an empty string.

Something along the lines of using this regular expression:
[^\n\r]*\r\n
Then use Regex.Matches().
The problem is you need Group(1) out of each match and create your string list from that. In Python you'd just use the map() function. Not sure the best way to do it in .NET, you take it from there ;-)

Dmitri, your solution is actually pretty compact and straightforward. The only thing more efficient would be to keep the string-splitting characters in the generated array, but the APIs simply don't allow for that. As a result, every solution will require iterating over the array and performing some kind of modification (which in C# means allocating new strings every time). I think the best you can hope for is to not re-create the array:
string[] lines = tbIn.Text.Split('\n');
for (int i = 0; i < lines.Length; ++i)
{
lines[i] = lines[i].Replace("\r", "\r\n");
}
... but as you can see that looks a lot more cumbersome! If performance matters, this may be a bit better. If it really matters, you should consider manually parsing the string by using IndexOf() to find the '\r's one at a time, and then create the array yourself. This is significantly more code, though, and probably not necessary.
One of the side effects of both your solution and this one is that you won't get a terminating "\r\n" on the last line if there wasn't one already there in the TextBox. Is this what you expect? What about blank lines... do you expect them to show up in 'lines'?

If you are just going to replace the newline (\n) then do something like this:
string[] lines = tbIn.Text.Split('\n')
.Select(t => t + "\r\n").ToArray();
Edit: Regex.Replace allows you to split on a string.
string[] lines = Regex.Split(tbIn.Text, "\r\n")
.Select(t => t + "\r\n").ToArray();

As always, extension method goodies :)
public static class StringExtensions
{
public static IEnumerable<string> SplitAndKeep(this string s, string seperator)
{
string[] obj = s.Split(new string[] { seperator }, StringSplitOptions.None);
for (int i = 0; i < obj.Length; i++)
{
string result = i == obj.Length - 1 ? obj[i] : obj[i] + seperator;
yield return result;
}
}
}
usage:
string text = "One,Two,Three,Four";
foreach (var s in text.SplitAndKeep(","))
{
Console.WriteLine(s);
}
Output:
One,
Two,
Three,
Four

You can achieve this with a regular expression. Here's an extension method with it:
public static string[] SplitAndKeepDelimiter(this string input, string delimiter)
{
MatchCollection matches = Regex.Matches(input, #"[^" + delimiter + "]+(" + delimiter + "|$)", RegexOptions.Multiline);
string[] result = new string[matches.Count];
for (int i = 0; i < matches.Count ; i++)
{
result[i] = matches[i].Value;
}
return result;
}
I'm not sure if this is a better solution. Yours is very compact and simple.