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Split a string if delimiter is between single quotes [duplicate]

This question already has answers here:
How to split csv whose columns may contain comma
(9 answers)
Closed 4 years ago.
I have the following comma-separated string that I need to split. The problem is that some of the content is within quotes and contains commas that shouldn't be used in the split.
String:
111,222,"33,44,55",666,"77,88","99"
I want the output:
111
222
33,44,55
666
77,88
99
I have tried this:
(?:,?)((?<=")[^"]+(?=")|[^",]+)
But it reads the comma between "77,88","99" as a hit and I get the following output:
111
222
33,44,55
666
77,88
,
99

Depending on your needs you may not be able to use a csv parser, and may in fact want to re-invent the wheel!!
You can do so with some simple regex
(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)
This will do the following:
(?:^|,) = Match expression "Beginning of line or string ,"
(\"(?:[^\"]+|\"\")*\"|[^,]*) = A numbered capture group, this will select between 2 alternatives:
stuff in quotes
stuff between commas
This should give you the output you are looking for.
Example code in C#
static Regex csvSplit = new Regex("(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)", RegexOptions.Compiled);
public static string[] SplitCSV(string input)
{
List<string> list = new List<string>();
string curr = null;
foreach (Match match in csvSplit.Matches(input))
{
curr = match.Value;
if (0 == curr.Length)
{
list.Add("");
}
list.Add(curr.TrimStart(','));
}
return list.ToArray();
}
private void button1_Click(object sender, RoutedEventArgs e)
{
Console.WriteLine(SplitCSV("111,222,\"33,44,55\",666,\"77,88\",\"99\""));
}
Warning As per #MrE's comment - if a rogue new line character appears in a badly formed csv file and you end up with an uneven ("string) you'll get catastrophic backtracking (https://www.regular-expressions.info/catastrophic.html) in your regex and your system will likely crash (like our production system did). Can easily be replicated in Visual Studio and as I've discovered will crash it. A simple try/catch will not trap this issue either.
You should use:
(?:^|,)(\"(?:[^\"])*\"|[^,]*)
instead

Fast and easy:
public static string[] SplitCsv(string line)
{
List<string> result = new List<string>();
StringBuilder currentStr = new StringBuilder("");
bool inQuotes = false;
for (int i = 0; i < line.Length; i++) // For each character
{
if (line[i] == '\"') // Quotes are closing or opening
inQuotes = !inQuotes;
else if (line[i] == ',') // Comma
{
if (!inQuotes) // If not in quotes, end of current string, add it to result
{
result.Add(currentStr.ToString());
currentStr.Clear();
}
else
currentStr.Append(line[i]); // If in quotes, just add it
}
else // Add any other character to current string
currentStr.Append(line[i]);
}
result.Add(currentStr.ToString());
return result.ToArray(); // Return array of all strings
}
With this string as input :
111,222,"33,44,55",666,"77,88","99"
It will return :
111
222
33,44,55
666
77,88
99

i really like jimplode's answer, but I think a version with yield return is a little bit more useful, so here it is:
public IEnumerable<string> SplitCSV(string input)
{
Regex csvSplit = new Regex("(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)", RegexOptions.Compiled);
foreach (Match match in csvSplit.Matches(input))
{
yield return match.Value.TrimStart(',');
}
}
Maybe it's even more useful to have it like an extension method:
public static class StringHelper
{
public static IEnumerable<string> SplitCSV(this string input)
{
Regex csvSplit = new Regex("(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)", RegexOptions.Compiled);
foreach (Match match in csvSplit.Matches(input))
{
yield return match.Value.TrimStart(',');
}
}
}

This regular expression works without the need to loop through values and TrimStart(','), like in the accepted answer:
((?<=\")[^\"]*(?=\"(,|$)+)|(?<=,|^)[^,\"]*(?=,|$))
Here is the implementation in C#:
string values = "111,222,\"33,44,55\",666,\"77,88\",\"99\"";
MatchCollection matches = new Regex("((?<=\")[^\"]*(?=\"(,|$)+)|(?<=,|^)[^,\"]*(?=,|$))").Matches(values);
foreach (var match in matches)
{
Console.WriteLine(match);
}
Outputs
111
222
33,44,55
666
77,88
99

None of these answers work when the string has a comma inside quotes, as in "value, 1", or escaped double-quotes, as in "value ""1""", which are valid CSV that should be parsed as value, 1 and value "1", respectively.
This will also work with the tab-delimited format if you pass in a tab instead of a comma as your delimiter.
public static IEnumerable<string> SplitRow(string row, char delimiter = ',')
{
var currentString = new StringBuilder();
var inQuotes = false;
var quoteIsEscaped = false; //Store when a quote has been escaped.
row = string.Format("{0}{1}", row, delimiter); //We add new cells at the delimiter, so append one for the parser.
foreach (var character in row.Select((val, index) => new {val, index}))
{
if (character.val == delimiter) //We hit a delimiter character...
{
if (!inQuotes) //Are we inside quotes? If not, we've hit the end of a cell value.
{
Console.WriteLine(currentString);
yield return currentString.ToString();
currentString.Clear();
}
else
{
currentString.Append(character.val);
}
} else {
if (character.val != ' ')
{
if(character.val == '"') //If we've hit a quote character...
{
if(character.val == '\"' && inQuotes) //Does it appear to be a closing quote?
{
if (row[character.index + 1] == character.val) //If the character afterwards is also a quote, this is to escape that (not a closing quote).
{
quoteIsEscaped = true; //Flag that we are escaped for the next character. Don't add the escaping quote.
}
else if (quoteIsEscaped)
{
quoteIsEscaped = false; //This is an escaped quote. Add it and revert quoteIsEscaped to false.
currentString.Append(character.val);
}
else
{
inQuotes = false;
}
}
else
{
if (!inQuotes)
{
inQuotes = true;
}
else
{
currentString.Append(character.val); //...It's a quote inside a quote.
}
}
}
else
{
currentString.Append(character.val);
}
}
else
{
if (!string.IsNullOrWhiteSpace(currentString.ToString())) //Append only if not new cell
{
currentString.Append(character.val);
}
}
}
}
}

With minor updates to the function provided by "Chad Hedgcock".
Updates are on:
Line 26: character.val == '\"' - This can never be true due to the check made on Line 24. i.e. character.val == '"'
Line 28: if (row[character.index + 1] == character.val) added !quoteIsEscaped to escape 3 consecutive quotes.
public static IEnumerable<string> SplitRow(string row, char delimiter = ',')
{
var currentString = new StringBuilder();
var inQuotes = false;
var quoteIsEscaped = false; //Store when a quote has been escaped.
row = string.Format("{0}{1}", row, delimiter); //We add new cells at the delimiter, so append one for the parser.
foreach (var character in row.Select((val, index) => new {val, index}))
{
if (character.val == delimiter) //We hit a delimiter character...
{
if (!inQuotes) //Are we inside quotes? If not, we've hit the end of a cell value.
{
//Console.WriteLine(currentString);
yield return currentString.ToString();
currentString.Clear();
}
else
{
currentString.Append(character.val);
}
} else {
if (character.val != ' ')
{
if(character.val == '"') //If we've hit a quote character...
{
if(character.val == '"' && inQuotes) //Does it appear to be a closing quote?
{
if (row[character.index + 1] == character.val && !quoteIsEscaped) //If the character afterwards is also a quote, this is to escape that (not a closing quote).
{
quoteIsEscaped = true; //Flag that we are escaped for the next character. Don't add the escaping quote.
}
else if (quoteIsEscaped)
{
quoteIsEscaped = false; //This is an escaped quote. Add it and revert quoteIsEscaped to false.
currentString.Append(character.val);
}
else
{
inQuotes = false;
}
}
else
{
if (!inQuotes)
{
inQuotes = true;
}
else
{
currentString.Append(character.val); //...It's a quote inside a quote.
}
}
}
else
{
currentString.Append(character.val);
}
}
else
{
if (!string.IsNullOrWhiteSpace(currentString.ToString())) //Append only if not new cell
{
currentString.Append(character.val);
}
}
}
}
}

For Jay's answer, if you use a 2nd boolean then you can have nested double-quotes inside single-quotes and vice-versa.
private string[] splitString(string stringToSplit)
{
char[] characters = stringToSplit.ToCharArray();
List<string> returnValueList = new List<string>();
string tempString = "";
bool blockUntilEndQuote = false;
bool blockUntilEndQuote2 = false;
int characterCount = 0;
foreach (char character in characters)
{
characterCount = characterCount + 1;
if (character == '"' && !blockUntilEndQuote2)
{
if (blockUntilEndQuote == false)
{
blockUntilEndQuote = true;
}
else if (blockUntilEndQuote == true)
{
blockUntilEndQuote = false;
}
}
if (character == '\'' && !blockUntilEndQuote)
{
if (blockUntilEndQuote2 == false)
{
blockUntilEndQuote2 = true;
}
else if (blockUntilEndQuote2 == true)
{
blockUntilEndQuote2 = false;
}
}
if (character != ',')
{
tempString = tempString + character;
}
else if (character == ',' && (blockUntilEndQuote == true || blockUntilEndQuote2 == true))
{
tempString = tempString + character;
}
else
{
returnValueList.Add(tempString);
tempString = "";
}
if (characterCount == characters.Length)
{
returnValueList.Add(tempString);
tempString = "";
}
}
string[] returnValue = returnValueList.ToArray();
return returnValue;
}

The original version
Currently I use the following regex:
public static Regex regexCSVSplit = new Regex(#"(?x:(
(?<FULL>
(^|[,;\t\r\n])\s*
( (?<QUODAT> (?<QUO>[""'])(?<DAT>([^,;\t\r\n]|(?<!\k<QUO>\s*)[,;\t\r\n])*)\k<QUO>) |
(?<QUODAT> (?<DAT> [^""',;\s\r\n]* )) )
(?=\s*([,;\t\r\n]|$))
) |
(?<FULL>
(^|[\s\t\r\n])
( (?<QUODAT> (?<QUO>[""'])(?<DAT> [^""',;\s\t\r\n]* )\k<QUO>) |
(?<QUODAT> (?<DAT> [^""',;\s\t\r\n]* )) )
(?=[,;\s\t\r\n]|$)
)
))", RegexOptions.Compiled);
This solution can handle pretty chaotic cases too like below:
This is how to feed the result into an array:
var data = regexCSVSplit.Matches(line_to_process).Cast<Match>().
Select(x => x.Groups["DAT"].Value).ToArray();
See this example in action HERE
Note: The regular expression contains two set of <FULL> block and each of them contains two <QUODAT> block separated by "or" (|). Depending on your task you may only need one of them.
Note: That this regular expression gives us one string array, and works on single line with or without <carrier return> and/or <line feed>.
Simplified version
The following regular expression will already cover many complex cases:
public static Regex regexCSVSplit = new Regex(#"(?x:(
(?<FULL>
(^|[,;\t\r\n])\s*
(?<QUODAT> (?<QUO>[""'])(?<DAT>([^,;\t\r\n]|(?<!\k<QUO>\s*)[,;\t\r\n])*)\k<QUO>)
(?=\s*([,;\t\r\n]|$))
)
))", RegexOptions.Compiled);
See this example in action: HERE
It can process complex, easy and empty items too:
This is how to feed the result into an array:
var data = regexCSVSplit.Matches(line_to_process).Cast<Match>().
Select(x => x.Groups["DAT"].Value).ToArray();
The main rule here is that every item may contain anything but the <quotation mark><separators><comma> sequence AND each item shall being and end with the same <quotation mark>.
<quotation mark>: <">, <'>
<comma>: <,>, <;>, <tab>, <carrier return>, <line feed>
Edit notes: I added some more explanation to make it easier to understand and replaces the text "CO" with "QUO".

Try this:
string s = #"111,222,""33,44,55"",666,""77,88"",""99""";
List<string> result = new List<string>();
var splitted = s.Split('"').ToList<string>();
splitted.RemoveAll(x => x == ",");
foreach (var it in splitted)
{
if (it.StartsWith(",") || it.EndsWith(","))
{
var tmp = it.TrimEnd(',').TrimStart(',');
result.AddRange(tmp.Split(','));
}
else
{
if(!string.IsNullOrEmpty(it)) result.Add(it);
}
}
//Results:
foreach (var it in result)
{
Console.WriteLine(it);
}

I know I'm a bit late to this, but for searches, here is how I did what you are asking about in C sharp
private string[] splitString(string stringToSplit)
{
char[] characters = stringToSplit.ToCharArray();
List<string> returnValueList = new List<string>();
string tempString = "";
bool blockUntilEndQuote = false;
int characterCount = 0;
foreach (char character in characters)
{
characterCount = characterCount + 1;
if (character == '"')
{
if (blockUntilEndQuote == false)
{
blockUntilEndQuote = true;
}
else if (blockUntilEndQuote == true)
{
blockUntilEndQuote = false;
}
}
if (character != ',')
{
tempString = tempString + character;
}
else if (character == ',' && blockUntilEndQuote == true)
{
tempString = tempString + character;
}
else
{
returnValueList.Add(tempString);
tempString = "";
}
if (characterCount == characters.Length)
{
returnValueList.Add(tempString);
tempString = "";
}
}
string[] returnValue = returnValueList.ToArray();
return returnValue;
}

Don't reinvent a CSV parser, try FileHelpers.

I needed something a little more robust, so I took from here and created this... This solution is a little less elegant and a little more verbose, but in my testing (with a 1,000,000 row sample), I found this to be 2 to 3 times faster. Plus it handles non-escaped, embedded quotes. I used string delimiter and qualifiers instead of chars because of the requirements of my solution. I found it more difficult than I expected to find a good, generic CSV parser so I hope this parsing algorithm can help someone.
public static string[] SplitRow(string record, string delimiter, string qualifier, bool trimData)
{
// In-Line for example, but I implemented as string extender in production code
Func <string, int, int> IndexOfNextNonWhiteSpaceChar = delegate (string source, int startIndex)
{
if (startIndex >= 0)
{
if (source != null)
{
for (int i = startIndex; i < source.Length; i++)
{
if (!char.IsWhiteSpace(source[i]))
{
return i;
}
}
}
}
return -1;
};
var results = new List<string>();
var result = new StringBuilder();
var inQualifier = false;
var inField = false;
// We add new columns at the delimiter, so append one for the parser.
var row = $"{record}{delimiter}";
for (var idx = 0; idx < row.Length; idx++)
{
// A delimiter character...
if (row[idx]== delimiter[0])
{
// Are we inside qualifier? If not, we've hit the end of a column value.
if (!inQualifier)
{
results.Add(trimData ? result.ToString().Trim() : result.ToString());
result.Clear();
inField = false;
}
else
{
result.Append(row[idx]);
}
}
// NOT a delimiter character...
else
{
// ...Not a space character
if (row[idx] != ' ')
{
// A qualifier character...
if (row[idx] == qualifier[0])
{
// Qualifier is closing qualifier...
if (inQualifier && row[IndexOfNextNonWhiteSpaceChar(row, idx + 1)] == delimiter[0])
{
inQualifier = false;
continue;
}
else
{
// ...Qualifier is opening qualifier
if (!inQualifier)
{
inQualifier = true;
}
// ...It's a qualifier inside a qualifier.
else
{
inField = true;
result.Append(row[idx]);
}
}
}
// Not a qualifier character...
else
{
result.Append(row[idx]);
inField = true;
}
}
// ...A space character
else
{
if (inQualifier || inField)
{
result.Append(row[idx]);
}
}
}
}
return results.ToArray<string>();
}
Some test code:
//var input = "111,222,\"33,44,55\",666,\"77,88\",\"99\"";
var input =
"111, 222, \"99\",\"33,44,55\" , \"666 \"mark of a man\"\", \" spaces \"77,88\" \"";
Console.WriteLine("Split with trim");
Console.WriteLine("---------------");
var result = SplitRow(input, ",", "\"", true);
foreach (var r in result)
{
Console.WriteLine(r);
}
Console.WriteLine("");
// Split 2
Console.WriteLine("Split with no trim");
Console.WriteLine("------------------");
var result2 = SplitRow(input, ",", "\"", false);
foreach (var r in result2)
{
Console.WriteLine(r);
}
Console.WriteLine("");
// Time Trial 1
Console.WriteLine("Experimental Process (1,000,000) iterations");
Console.WriteLine("-------------------------------------------");
watch = Stopwatch.StartNew();
for (var i = 0; i < 1000000; i++)
{
var x1 = SplitRow(input, ",", "\"", false);
}
watch.Stop();
elapsedMs = watch.ElapsedMilliseconds;
Console.WriteLine($"Total Process Time: {string.Format("{0:0.###}", elapsedMs / 1000.0)} Seconds");
Console.WriteLine("");
Results
Split with trim
---------------
111
222
99
33,44,55
666 "mark of a man"
spaces "77,88"
Split with no trim
------------------
111
222
99
33,44,55
666 "mark of a man"
spaces "77,88"
Original Process (1,000,000) iterations
-------------------------------
Total Process Time: 7.538 Seconds
Experimental Process (1,000,000) iterations
--------------------------------------------
Total Process Time: 3.363 Seconds

I once had to do something similar and in the end I got stuck with Regular Expressions. The inability for Regex to have state makes it pretty tricky - I just ended up writing a simple little parser.
If you're doing CSV parsing you should just stick to using a CSV parser - don't reinvent the wheel.

Here is my fastest implementation based upon string raw pointer manipulation:
string[] FastSplit(string sText, char? cSeparator = null, char? cQuotes = null)
{
string[] oTokens;
if (null == cSeparator)
{
cSeparator = DEFAULT_PARSEFIELDS_SEPARATOR;
}
if (null == cQuotes)
{
cQuotes = DEFAULT_PARSEFIELDS_QUOTE;
}
unsafe
{
fixed (char* lpText = sText)
{
#region Fast array estimatation
char* lpCurrent = lpText;
int nEstimatedSize = 0;
while (0 != *lpCurrent)
{
if (cSeparator == *lpCurrent)
{
nEstimatedSize++;
}
lpCurrent++;
}
nEstimatedSize++; // Add EOL char(s)
string[] oEstimatedTokens = new string[nEstimatedSize];
#endregion
#region Parsing
char[] oBuffer = new char[sText.Length];
int nIndex = 0;
int nTokens = 0;
lpCurrent = lpText;
while (0 != *lpCurrent)
{
if (cQuotes == *lpCurrent)
{
// Quotes parsing
lpCurrent++; // Skip quote
nIndex = 0; // Reset buffer
while (
(0 != *lpCurrent)
&& (cQuotes != *lpCurrent)
)
{
oBuffer[nIndex] = *lpCurrent; // Store char
lpCurrent++; // Move source cursor
nIndex++; // Move target cursor
}
}
else if (cSeparator == *lpCurrent)
{
// Separator char parsing
oEstimatedTokens[nTokens++] = new string(oBuffer, 0, nIndex); // Store token
nIndex = 0; // Skip separator and Reset buffer
}
else
{
// Content parsing
oBuffer[nIndex] = *lpCurrent; // Store char
nIndex++; // Move target cursor
}
lpCurrent++; // Move source cursor
}
// Recover pending buffer
if (nIndex > 0)
{
// Store token
oEstimatedTokens[nTokens++] = new string(oBuffer, 0, nIndex);
}
// Build final tokens list
if (nTokens == nEstimatedSize)
{
oTokens = oEstimatedTokens;
}
else
{
oTokens = new string[nTokens];
Array.Copy(oEstimatedTokens, 0, oTokens, 0, nTokens);
}
#endregion
}
}
// Epilogue
return oTokens;
}

Try this
private string[] GetCommaSeperatedWords(string sep, string line)
{
List<string> list = new List<string>();
StringBuilder word = new StringBuilder();
int doubleQuoteCount = 0;
for (int i = 0; i < line.Length; i++)
{
string chr = line[i].ToString();
if (chr == "\"")
{
if (doubleQuoteCount == 0)
doubleQuoteCount++;
else
doubleQuoteCount--;
continue;
}
if (chr == sep && doubleQuoteCount == 0)
{
list.Add(word.ToString());
word = new StringBuilder();
continue;
}
word.Append(chr);
}
list.Add(word.ToString());
return list.ToArray();
}

This is Chad's answer rewritten with state based logic. His answered failed for me when it came across """BRAD""" as a field. That should return "BRAD" but it just ate up all the remaining fields. When I tried to debug it I just ended up rewriting it as state based logic:
enum SplitState { s_begin, s_infield, s_inquotefield, s_foundquoteinfield };
public static IEnumerable<string> SplitRow(string row, char delimiter = ',')
{
var currentString = new StringBuilder();
SplitState state = SplitState.s_begin;
row = string.Format("{0}{1}", row, delimiter); //We add new cells at the delimiter, so append one for the parser.
foreach (var character in row.Select((val, index) => new { val, index }))
{
//Console.WriteLine("character = " + character.val + " state = " + state);
switch (state)
{
case SplitState.s_begin:
if (character.val == delimiter)
{
/* empty field */
yield return currentString.ToString();
currentString.Clear();
} else if (character.val == '"')
{
state = SplitState.s_inquotefield;
} else
{
currentString.Append(character.val);
state = SplitState.s_infield;
}
break;
case SplitState.s_infield:
if (character.val == delimiter)
{
/* field with data */
yield return currentString.ToString();
state = SplitState.s_begin;
currentString.Clear();
} else
{
currentString.Append(character.val);
}
break;
case SplitState.s_inquotefield:
if (character.val == '"')
{
// could be end of field, or escaped quote.
state = SplitState.s_foundquoteinfield;
} else
{
currentString.Append(character.val);
}
break;
case SplitState.s_foundquoteinfield:
if (character.val == '"')
{
// found escaped quote.
currentString.Append(character.val);
state = SplitState.s_inquotefield;
}
else if (character.val == delimiter)
{
// must have been last quote so we must find delimiter
yield return currentString.ToString();
state = SplitState.s_begin;
currentString.Clear();
}
else
{
throw new Exception("Quoted field not terminated.");
}
break;
default:
throw new Exception("unknown state:" + state);
}
}
//Console.WriteLine("currentstring = " + currentString.ToString());
}
This is a lot more lines of code than the other solutions, but it is easy to modify to add edge cases.

Writing a program in C# where depending on the Id (txtBxNumber) it will either update or create a new record in a text file and a Rich Text Box

fileName = txtBxFileNamePath.Text;
if (File.Exists(fileName))
{
if (txtBxDate.Text != null && txtBxNumber.Text != null && txtBxUnit.Text != null && txtBxUnitPrice.Text != null && txtBxShipTo.Text != null
&& txtBxOrdered.Text != null && richTxBxDesc.Text != null)
{
try
{
int higherThanZero = Int32.Parse(txtBxNumber.Text);
if (higherThanZero > 0)
{
using (StreamReader reader = File.OpenText(fileName))
{
string[] lines = File.ReadAllLines(fileName);
for (int i = 0; i < lines.Length - 1; i++)
{
string firstNum = lines[i].Substring(0, 2);
if (firstNum == txtBxNumber.Text)
{
string record = "hello ";
lines[i].Replace(lines[i], record);
}
else
{
int orderNum = Int32.Parse(txtBxOrdered.Text);
int unitPriceNum = Int32.Parse(txtBxUnitPrice.Text);
double tax = .13;
int taxInt = (int)tax;
int amount = orderNum * unitPriceNum;
string amountStr = amount.ToString();
int amountTotal = amount * taxInt;
string amountTotalStr = amountTotal.ToString();
amountList.Add(amountStr);
amountTotalList.Add(amountTotalStr);
string record = amountTotalStr.PadRight(30) + amountStr.PadRight(30);
richTxtBxRecord.Text += record + "\n";
using (StreamWriter write = new StreamWriter(fileName, true))
{
write.WriteLine(record + "\n");
write.Close();
}
}
}
}
}
else
{
richTxtBxError.Text += "Textbox Number must contain a digit higher than 0 ";
}
}
catch
{
richTxtBxError.Text += "Please make sure number text box is a digit";
}
}
else
{
richTxtBxError.Text += "please make sure that no text boxes are empty";
}
}
else
{
richTxtBxError.Text += "Please select a file that already exists";
}
I am having an issue where once i get past the try-catch statement "please make sure number is a digit, no code executes. I am trying to obtain the first few characters in a text file and match it with the users input. If the input is the same as what is already inserted in the text file, i update the whole record. If there is no match (non existent number) i write in a brand new record.

I can't quite follow your logic, but I tried. You should be able to take this code and do what you want (whatever it is).
I started by declaring some class level variables.
private DateTime _dateValue;
private int _numberValue;
private decimal _unitPrice;
private int _numberOrdered;
Then, since you have so many preconditions and so many text boxes, I factored out the validation and setting of these variables. It makes the logic (whatever it supposed to be) much easier to follow:
private bool ValidateUserEntry()
{
bool isError = false;
if (!File.Exists(txtBxFileNamePath.Text))
{
AddError("File Name must exist");
isError = true;
}
if (txtBxDate.Text == string.Empty || !DateTime.TryParse(txtBxDate.Text, out var _dateValue))
{
AddError("The date must be a valid date");
isError = true;
}
if (txtBxNumber.Text == string.Empty || !int.TryParse(txtBxNumber.Text, out _numberValue) ||
_numberValue <= 0)
{
AddError("You must enter a number greater than 0 for [Number]");
isError = true;
}
if (txtBxUnitPrice.Text == string.Empty || !decimal.TryParse(txtBxUnitPrice.Text, out _unitPrice) ||
_unitPrice <= 0.0m)
{
AddError("The unit price must be a positive decimal number");
isError = true;
}
if (txtBxShipTo.Text == string.Empty)
{
AddError("A ship to address is required");
isError = true;
}
if (txtBxOrdered.Text == string.Empty || !int.TryParse(txtBxOrdered.Text, out _numberOrdered) ||
_numberOrdered <= 0)
{
AddError("The Number ordered must be a number greater than 0");
isError = true;
}
if (richTxBxDesc.Text == string.Empty)
{
AddError("A description is required");
isError = true;
}
return !isError;
}
I also added two utility functions for managing the error list:
private void ClearError()
{
richTxtBxError.Text = string.Empty;
}
private void AddError(string errorMessage)
{
richTxtBxError.Text += (errorMessage + Environment.NewLine);
richTxtBxError.SelectionStart = richTxtBxError.Text.Length;
richTxtBxError.SelectionLength = 0;
}
Now comes the real code. Near as I can tell, you want to scan a text file. If the number in the first few character positions matches a number in your input, then you change the line to some constant text. Otherwise, you want to do a calculation and put the results of the calculation on the line of text.
My input file looks like this:
1 First
2 Second
3 Third
12 Twelth
13 Thirteenth
34 Thirty-fourth
and the code that I run looks like what's below. The logic makes no sense, but it was what I could discern from your code. Instead of trying to do things on the fly to a file (which never really turns out well unless you are really careful), I gather the output into a List<string>. Once I have all the output, I put it in a text box control and overwrite the file.
ClearError();
//check pre-conditions
if (!ValidateUserEntry())
{
return;
}
string[] lines;
using (StreamReader reader = File.OpenText(txtBxFileNamePath.Text))
{
lines = File.ReadAllLines(txtBxFileNamePath.Text);
}
List<string> newLines = new List<string>();
for (var lineIndex = 0; lineIndex < lines.Length; ++lineIndex)
{
var line = lines[lineIndex];
if (line.Length > 2 && int.TryParse(line.Substring(0, 2), out var linePrefixNumber) &&
linePrefixNumber == _numberValue)
{
newLines.Add("Bingo, hit the right record");
}
else
{
decimal tax = .13m;
var amount = _numberOrdered * _unitPrice;
var amountTotal = amount * (1m + tax);
//amountList.Add(amount.TosString());
//amountTotalList.Add(amountTotal.ToString());
var newRecord = $"{amountTotal,30:C}{amount,30:C}";
newLines.Add(newRecord); //every record but one will be the same, but, such is life
}
}
//at this point, the newLines list has what I want
//put it in the text box
richTxtBxRecord.Text = string.Join(Environment.NewLine, newLines);
//and write it out
using (StreamWriter write = new StreamWriter(txtBxFileNamePath.Text, append:false))
{
write.Write(richTxtBxRecord.Text);
write.Flush();
}
With inputs that look like:
Number: 12
Number Ordered: 3
Unit Price: 1.23
The output (oddly enough - but it's what I could figure from your code) looks like:
$4.17 $3.69
$4.17 $3.69
$4.17 $3.69
Bingo, hit the right record
$4.17 $3.69
$4.17 $3.69
You can see that the input line that had the 12 at the start gets switched for bingo. The rest get the same information. I'm sure that's not what you want. But, with this code, you should be able to get something that you'd like.
Also note that I treat all the currency values as decimal (not int or double). For the life of me, I have no idea what you were trying to do with the taxInt variable (it will always be zero the way you have coded it). Instead, I did a rational tax calculation.

All of the code below the catch block is inside an else block, so I wouldn't expect it to execute. If you want something to execute after the catch, remove it from the else block.

C# RichTextBox Line-by-line scan

Hey Im creating my own coding language and I already have the entire application set up with save, open, close, new, etc.
In order for the "Run" part to work, I need a way to scan and test every single line in richTextBox1.
Maybe for past Java users, something along the lines of the "java-util-scanner," but easier to use for testing each line.
Does anyone know a way to do this, where a string "scannedString" would be tested as so:
if(scannedString == "#load(moduleFiles)") {
//action here
}
string scannedStringNextLine = ???
if(scannedStringNextLine = "") {
//action here
}
Eventually it would look more like this:
if(scannedString == "code1" || scannedString == "code2" etc... ) {
if(scannedString == "code1") {
//action here
}
} else {
//error message
}
hope this is enough information...

To get lines of code of the RichTextBox you can split the content by a new line symbol:
var lines = this.richTextBox.Text.Split('\n').ToList();
The lines are in order of appearance. Then you can go through lines in a for or foreach loop:
foreach (var line in lines)
{
// access a line, evaluate it, etc.
}

One way to do it is to split the text on the newline charaters and then parse each line for the text you care about:
private void btnScan_Click(object sender, EventArgs e)
{
var code = richTextBox1.Text;
foreach (var line in code.Split(new []{'\n','\r'},
StringSplitOptions.RemoveEmptyEntries))
{
CheckForLoad(line);
}
}
void CheckForLoad(string line)
{
if (string.IsNullOrWhiteSpace(line)) return;
int i = line.IndexOf("#load");
if (i < 0) return;
int openParen = line.IndexOf("(", i + 1);
if (openParen < 0) return;
int closeParen = line.IndexOf(")", openParen + 1);
if (closeParen < 0) return;
string modules = line.Substring(openParen + 1, closeParen - openParen - 1);
MessageBox.Show(string.Format("Loading modules: {0}", modules));
}

Parsing CSV strings (not files) in C#

Using C#, I need to parse a CSV string that doesn't come from a file. I've found a great deal of material on parsing CSV files, but virtually nothing on strings. It seems as though this should be simple, yet thus far I can come up only with inefficient methods, such as this:
using Microsoft.VisualBasic.FileIO;
var csvParser = new TextFieldParser(new StringReader(strCsvLine));
csvParser.SetDelimiters(new string[] { "," });
csvParser.HasFieldsEnclosedInQuotes = true;
Are there good ways of making this more efficient and less ugly? I will be processing huge volumes of strings, so I wouldn't want to pay the cost of all the above. Thanks.

Here is a lightly tested parser that handles quotes
List<string> Parse(string line)
{
var columns = new List<string>();
var sb = new StringBuilder();
bool isQuoted = false;
int nQuotes = 0;
foreach(var c in line)
{
if (sb.Length == 0 && !isQuoted && c == '"')
{
isQuoted = true;
continue;
}
if (isQuoted)
{
if (c == '"')
{
nQuotes++;
continue;
}
else
{
if (nQuotes > 0)
{
sb.Append('"', nQuotes / 2);
if (nQuotes % 2 != 0)
{
isQuoted = false;
}
nQuotes = 0;
}
}
}
if (!isQuoted && c == ',')
{
columns.Add(sb.ToString());
sb.Clear();
continue;
}
sb.Append(c);
}
if (nQuotes > 0)
{
sb.Append('"', nQuotes / 2);
}
columns.Add(sb.ToString());
return columns;
}

c# search string in txt file

I want to find a string in a txt file if string compares, it should go on reading lines till another string which I'm using as parameter.
Example:
CustomerEN //search for this string
...
some text which has details about the customer
id "123456"
username "rootuser"
...
CustomerCh //get text till this string
I need the details to work with them otherwise.
I'm using linq to search for "CustomerEN" like this:
File.ReadLines(pathToTextFile).Any(line => line.Contains("CustomerEN"))
But now I'm stuck with reading lines (data) till "CustomerCh" to extract details.

If your pair of lines will only appear once in your file, you could use
File.ReadLines(pathToTextFile)
.SkipWhile(line => !line.Contains("CustomerEN"))
.Skip(1) // optional
.TakeWhile(line => !line.Contains("CustomerCh"));
If you could have multiple occurrences in one file, you're probably better off using a regular foreach loop - reading lines, keeping track of whether you're currently inside or outside a customer etc:
List<List<string>> groups = new List<List<string>>();
List<string> current = null;
foreach (var line in File.ReadAllLines(pathToFile))
{
if (line.Contains("CustomerEN") && current == null)
current = new List<string>();
else if (line.Contains("CustomerCh") && current != null)
{
groups.Add(current);
current = null;
}
if (current != null)
current.Add(line);
}

You have to use while since foreach does not know about index. Below is an example code.
int counter = 0;
string line;
Console.Write("Input your search text: ");
var text = Console.ReadLine();
System.IO.StreamReader file =
new System.IO.StreamReader("SampleInput1.txt");
while ((line = file.ReadLine()) != null)
{
if (line.Contains(text))
{
break;
}
counter++;
}
Console.WriteLine("Line number: {0}", counter);
file.Close();
Console.ReadLine();

With LINQ, you could use the SkipWhile / TakeWhile methods, like this:
var importantLines =
File.ReadLines(pathToTextFile)
.SkipWhile(line => !line.Contains("CustomerEN"))
.TakeWhile(line => !line.Contains("CustomerCh"));

If you whant only one first string, you can use simple for-loop.
var lines = File.ReadAllLines(pathToTextFile);
var firstFound = false;
for(int index = 0; index < lines.Count; index++)
{
if(!firstFound && lines[index].Contains("CustomerEN"))
{
firstFound = true;
}
if(firstFound && lines[index].Contains("CustomerCh"))
{
//do, what you want, and exit the loop
// return lines[index];
}
}

I worked a little bit the method that Rawling posted here to find more than one line in the same file until the end. This is what worked for me:
foreach (var line in File.ReadLines(pathToFile))
{
if (line.Contains("CustomerEN") && current == null)
{
current = new List<string>();
current.Add(line);
}
else if (line.Contains("CustomerEN") && current != null)
{
current.Add(line);
}
}
string s = String.Join(",", current);
MessageBox.Show(s);