I have a string
"[\"1,1\",\"2,2\"]"
and I want to turn this string onto this
1,1,2,2
I am using Replace function for that like
obj.str.Replace("[","").Replace("]","").Replace("\\","");
But it does not return the expected result.
Please help.
You haven't removed the double quotes. Use the following:
obj.str = obj.str.Replace("[","").Replace("]","").Replace("\\","").Replace("\"", "");
Here is an optimized approach in case the string or the list of exclude-characters is long:
public static class StringExtensions
{
public static String RemoveAll(this string input, params Char[] charactersToRemove)
{
if(string.IsNullOrEmpty(input) || (charactersToRemove==null || charactersToRemove.Length==0))
return input;
var exclude = new HashSet<Char>(charactersToRemove); // removes duplicates and has constant lookup time
var sb = new StringBuilder(input.Length);
foreach (Char c in input)
{
if (!exclude.Contains(c))
sb.Append(c);
}
return sb.ToString();
}
}
Use it in this way:
str = str.RemoveAll('"', '[', ']', '\\');
// or use a string as "remove-array":
string removeChars = "\"{[]\\";
str = str.RemoveAll(removeChars.ToCharArray());
You should do following:
obj.str = obj.str.Replace("[","").Replace("]","").Replace("\"","");
string.Replace method does not replace string content in place. This means that if you have
string test = "12345" and do
test.Replace("2", "1");
test string will still be "12345". Replace doesn't change string itself, but creates new string with replaced content. So you need to assign this new string to a new or same variable
changedTest = test.Replace("2", "1");
Now, changedTest will containt "11345".
Another note on your code is that you don't actually have \ character in your string. It's only displayed in order to escape quote character. If you want to know more about this, please read MSDN article on string literals.
how about
var exclusions = new HashSet<char>(new[] { '"', '[', ']', '\\' });
return new string(obj.str.Where(c => !exclusions.Contains(c)).ToArray());
To do it all in one sweep.
As Tim Schmelter writes, if you wanted to do it often, especially with large exclusion sets over long strings, you could make an extension like this.
public static string Strip(
this string source,
params char[] exclusions)
{
if (!exclusions.Any())
{
return source;
}
var mask = new HashSet<char>(exclusions);
var result = new StringBuilder(source.Length);
foreach (var c in source.Where(c => !mask.Contains(c)))
{
result.Append(c);
}
return result.ToString();
}
so you could do,
var result = "[\"1,1\",\"2,2\"]".Strip('"', '[', ']', '\\');
Capture the numbers only with this regular expression [0-9]+ and then concatenate the matches:
var input = "[\"1,1\",\"2,2\"]";
var regex = new Regex("[0-9]+");
var matches = regex.Matches(input).Cast<Match>().Select(m => m.Value);
var result = string.Join(",", matches);
Related
I'm trying to find a cleaner way of performing multiple sequential replacements on a single string where each replacement has a unique pattern and string replacement.
For example, if I have 3 pairs of patterns-substitutions strings:
1. /(?<!\\)\\n/, "\n"
2. /(\\)(?=[\;\:\,])/, ""
3. /(\\{2})/, "\\"
I want to apply regex replacement 1 on the original string, then apply 2 on the output of 1, and so on and so forth.
The following console program example does exactly what I want, but it has a lot of repetition, I am looking for a cleaner way to do the same thing.
SanitizeString
static public string SanitizeString(string param)
{
string retval = param;
//first replacement
Regex SanitizePattern = new Regex(#"([\\\;\:\,])");
retval = SanitizePattern.Replace(retval, #"\$1");
//second replacement
SanitizePattern = new Regex(#"\r\n?|\n");
retval = SanitizePattern.Replace(retval, #"\n");
return retval;
}
ParseCommands
static public string ParseCommands(string param)
{
string retval = param;
//first replacement
Regex SanitizePattern = new Regex(#"(?<!\\)\\n");
retval = SanitizePattern.Replace(retval, System.Environment.NewLine);
//second replacement
SanitizePattern = new Regex(#"(\\)(?=[\;\:\,])");
retval = SanitizePattern.Replace(retval, "");
//third replacement
SanitizePattern = new Regex(#"(\\{2})");
retval = SanitizePattern.Replace(retval, #"\");
return retval;
}
Main
using System;
using System.IO;
using System.Text.RegularExpressions;
...
static void Main(string[] args)
{
//read text that contains user input
string sampleText = File.ReadAllText(#"c:\sample.txt");
//sanitize input with certain rules
sampleText = SanitizeString(sampleText);
File.WriteAllText(#"c:\sanitized.txt", sampleText);
//parses escaped characters back into the original text
sampleText = ParseCommands(sampleText);
File.WriteAllText(#"c:\parsed_back.txt", sampleText);
}
Don't mind the file operations. I just used that as a quick way to visualize the actual output. In my program I'm going to use something different.
Here's one way:
var replacements = new List<(Regex regex, string replacement)>()
{
(new Regex(#"(?<!\\)\\n"), System.Environment.NewLine),
(new Regex(#"(\\)(?=[\;\:\,])"), ""),
(new Regex(#"(\\{2})"), #"\"),
};
(Ideally cache that in a static readonly field):
Then:
string retval = param;
foreach (var (regex, replacement) in replacements)
{
retval = regex.Replace(retval, replacement);
}
Or you could go down the linq route:
string retval = replacements
.Aggregate(param, (str, x) => x.regex.Replace(str, x.replacement));
I was not clear with my previous question
I have a list: new List<string> { "lts", "mts", "cwts", "rotc" };
Now I wan't to check a pattern in string that starts or ends with a forward slash like this: "cTws/Rotc/lTs" or "SomethingcTws cWtS/Rotc rOtc".
and convert to upper case only the string that starts/ends with a forward slash based on the list that I have.
So the output should be: "CWTS/ROTC/LTS", "SomethingcTws CWTS/ROTC rOtc"
I modified Sachin's answer:
List<string> replacementValues = new List<string>
{
"cwts",
"mts",
"rotc",
"lts"
};
string pattern = string.Format(#"\G({0})/?", string.Join("|", replacementValues.Select(x => Regex.Escape(x))));
Regex regExp = new Regex(pattern, RegexOptions.IgnoreCase);
string value = "Cwts/Rotc Somethingcwts1 Cwts/Rotc/lTs";
string result = regExp.Replace(value, s => s.Value.ToUpper());
Result: CWTS/ROTC Somethingcwts1 Cwts/Rotc/lTs
The desired output should be: CWTS/ROTC Somethingcwts1 CWTS/ROTC/LTS
So instead of using Regex, which I'm not really good with, I'm doing split by space then split by "/" then rejoin the strings
string val = "Somethingrotc1 cWts/rOtC/lTs Cwts";
List<string> replacementValues = new List<string>
{
"lts", "mts",
"cwts", "rotc"
};
string[] tokens = val.Split(new char[] { ' ' }, StringSplitOptions.None);
string result = string.Join(" ", tokens.Select(t =>
{
// Now split by "/"
string[] ts = t.Split(new char[] { '/' }, StringSplitOptions.None);
if (ts.Length > 1)
{
t = string.Join("/", ts.Select(x => replacementValues.Contains(x.ToLower()) ? x.ToUpper() : x));
}
return t;
}));
Output: Somethingrotc1 CWTS/ROTC/LTS Cwts
You want to change the specific words in the string to Upper case. Then you can use Regex to achieve it.
string value = "Somethingg1 Cwts/Rotc/Lts Cwts";
var replacementValues = new Dictionary<string, string>()
{
{"Cwts","CWTS"},
{"Rotc","ROTC"},
{"Lts","LTC"}
};
var regExpression = new Regex(String.Join("|", replacementValues.Keys.Select(x => Regex.Escape(x))));
var outputString = regExpression.Replace(value, s => replacementValues[s.Value]);
I found some solutions for my problem, which is quite simple:
I have a string, which is looking like this:
"\r\nContent-Disposition: form-data; name=\"ctl00$cphMainContent$grid$ctl03$ucPicture$ctl00\""
My goal is to break it down, so I have a Dictionary of values, like:
Key = "name", value ? "ctl..."
My approach was: Split it by "\r\n" and then by the equal or the colon sign.
This worked fine, but then some funny Tester uploaded a file with all allowed charactes, which made the String looking like this:
"\r\nContent-Disposition: form-data; name=\"ctl00_cphMainContent_grid_ctl03_ucPicture_btnUpload$fileUpload\"; filename=\"C:\\Users\\matthias.mueller\\Desktop\\- ie+![]{}_-´;,.$¨##ç %&()=~^`'.jpg\"\r\nContent-Type: image/jpeg"
Of course, the simple splitting doesn't work anymore, since it splits now the filename.
I corrected this by reading out "filename=" and escaping the signs I'm looking to split, and then creating a regex.
Now comes my problem: I found two Regex-samples, which could do the work for the equal sign, the semicolon and the colon. one is:
[^\\]=
The other one I found was:
(?<!\\\\)=
The problem is, the first one doesn't only split, but it splits the equal sign and one character before this sign, which means my key in the Dictionary is "nam" instead of "name"
The second one works fine on this matter, but it still splits the escaped equal sign in the filename.
Is my approach for this problem even working? Would there be a better solution for this? And why is the first Regex cutting a character?
Edit: To avoid confusion, my escaped String looks like this:
"Content-Disposition: form-data; name=\"ctl00_cphMainContent_grid_ctl03_ucPicture_btnUpload$fileUpload\"; filename=\"C\:\Users\matthias.mueller\Desktop\- ie+![]{}_-´\;,.$¨##ç %&()\=~^`'.jpg\""
So I want basically: Split by equal Sign EXCEPT the escaped ones. By the way: The string here shows only one \, but there are 2.
Edit 2: OK seems like I have a working solution, but it's so ugly:
Dictionary<string, string> ParseHeader(byte[] bytes, int pos)
{
Dictionary<string, string> items;
string header;
string[] headerLines;
int start;
int end;
string input = _encoding.GetString(bytes, pos, bytes.Length - pos);
start = input.IndexOf("\r\n", 0);
if (start < 0) return null;
end = input.IndexOf("\r\n\r\n", start);
if (end < 0) return null;
WriteBytes(false, bytes, pos, end + 4 - 0); // Write the header to the form content
header = input.Substring(start, end - start);
items = new Dictionary<string, string>();
headerLines = Regex.Split(header, "\r\n");
Regex regLineParts = new Regex(#"(?<!\\\\);");
Regex regColon = new Regex(#"(?<!\\\\):");
Regex regEqualSign = new Regex(#"(?<!\\\\)=");
foreach (string hl in headerLines)
{
string workString = hl;
//Escape the Semicolon in filename
if (hl.Contains("filename"))
{
String orig = hl.Substring(hl.IndexOf("filename=\"") + 10);
orig = orig.Substring(0, orig.IndexOf('"'));
string toReplace = orig;
toReplace = toReplace.Replace(toReplace, toReplace.Replace(";", #"\\;"));
toReplace = toReplace.Replace(toReplace, toReplace.Replace(":", #"\\:"));
toReplace = toReplace.Replace(toReplace, toReplace.Replace("=", #"\\="));
workString = hl.Replace(orig, toReplace);
}
string[] lineParts = regLineParts.Split(workString);
for (int i = 0; i < lineParts.Length; i++)
{
string[] p;
if (i == 0)
p = regColon.Split(lineParts[i]);
else
p = regEqualSign.Split(lineParts[i]);
if (p.Length == 2)
{
string orig = p[0];
orig = orig.Replace(#"\\;", ";");
orig = orig.Replace(#"\\:", ":");
orig = orig.Replace(#"\\=", "=");
p[0] = orig;
orig = p[1];
orig = orig.Replace(#"\\;", ";");
orig = orig.Replace(#"\\:", ":");
orig = orig.Replace(#"\\=", "=");
p[1] = orig;
items.Add(p[0].Trim(), p[1].Trim());
}
}
}
return items;
}
Needs some further testing.
I had a go at writing a parser for you. It handles literal strings, like "here is a string", as the values in name-value pairs. I've also written a few tests, and the last shows an '=' character inside a literal string. It also handles escaping quotes (") inside literal strings by escaping as \" -- I'm not sure if this is right, but you could change it.
A quick explanation. I first find anything that looks like a literal string and replace it with a value like PLACEHOLDER8230498234098230498. This means the whole thing is now literal name-value pairs; eg
key="value"
becomes
key=PLACEHOLDER8230498234098230498
The original string value is stored off in the literalStrings dictionary for later.
So now we split on semicolons (to get key=value strings) and then on equals, to get the proper key/value pairs.
Then I substitute the placeholder values back in before returning the result.
public class HttpHeaderParser
{
public NameValueCollection Parse(string header)
{
var result = new NameValueCollection();
// 'register' any string values;
var stringLiteralRx = new Regex(#"""(?<content>(\\""|[^\""])+?)""", RegexOptions.IgnorePatternWhitespace);
var equalsRx = new Regex("=", RegexOptions.IgnorePatternWhitespace);
var semiRx = new Regex(";", RegexOptions.IgnorePatternWhitespace);
Dictionary<string, string> literalStrings = new Dictionary<string, string>();
var cleanedHeader = stringLiteralRx.Replace(header, m =>
{
var replacement = "PLACEHOLDER" + Guid.NewGuid().ToString("N");
var stringLiteral = m.Groups["content"].Value.Replace("\\\"", "\"");
literalStrings.Add(replacement, stringLiteral);
return replacement;
});
// now it's safe to split on semicolons to get name-value pairs
var nameValuePairs = semiRx.Split(cleanedHeader);
foreach(var nameValuePair in nameValuePairs)
{
var nameAndValuePieces = equalsRx.Split(nameValuePair);
var name = nameAndValuePieces[0].Trim();
var value = nameAndValuePieces[1];
string replacementValue;
if (literalStrings.TryGetValue(value, out replacementValue))
{
value = replacementValue;
}
result.Add(name, value);
}
return result;
}
}
There's every chance there are some proper bugs in it.
Here's some unit tests you should incorporate, too;
[TestMethod]
public void TestMethod1()
{
var tests = new[] {
new { input=#"foo=bar; baz=quux", expected = #"foo|bar^baz|quux"},
new { input=#"foo=bar;baz=""quux""", expected = #"foo|bar^baz|quux"},
new { input=#"foo=""bar"";baz=""quux""", expected = #"foo|bar^baz|quux"},
new { input=#"foo=""b,a,r"";baz=""quux""", expected = #"foo|b,a,r^baz|quux"},
new { input=#"foo=""b;r"";baz=""quux""", expected = #"foo|b;r^baz|quux"},
new { input=#"foo=""b\""r"";baz=""quux""", expected = #"foo|b""r^baz|quux"},
new { input=#"foo=""b=r"";baz=""quux""", expected = #"foo|b=r^baz|quux"},
};
var parser = new HttpHeaderParser();
foreach(var test in tests)
{
var actual = parser.Parse(test.input);
var actualAsString = String.Join("^", actual.Keys.Cast<string>().Select(k => string.Format("{0}|{1}", k, actual[k])));
Assert.AreEqual(test.expected, actualAsString);
}
}
Looks to me like you'll need a bit more of a solid parser for this than a regex split. According to this page the name/value pairs can either be 'raw';
x=1
or quoted;
x="foo bar baz"
So you'll need to look for a solution that not only splits on the equals, but ignores any equals inside;
x="y=z"
It might be that there is a better or more managed way for you to access this info. If you are using a classic ASP.NET WebForms FileUpload control, you can access the filename using the properties of the control, like
FileUpload1.HasFile
FileUpload1.FileName
If you're using MVC, you can use the HttpPostedFileBase class as a parameter to the action method. See this answer
[HttpPost]
public ActionResult Index(HttpPostedFileBase file)
{
// Verify that the user selected a file
if (file != null && file.ContentLength > 0)
{
// extract only the fielname
var fileName = Path.GetFileName(file.FileName);
// store the file inside ~/App_Data/uploads folder
var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
file.SaveAs(path);
}
// redirect back to the index action to show the form once again
return RedirectToAction("Index");
}
This:
(?<!\\\\)=
matches = not preceded by \\.
It should be:
(?<!\\)=
(Make sure you use # (verbatim) strings for the regex, to avoid confusion)
I have different string that starts and ends with { } like so {somestring}. I want to remove the delimiters from the string so that it shows somestring only. I can't do anything that counts the letters because I don't always know the length of the string.
Maybe this will help. Here is the code, somewhere here I want to delete the delimiters.
private static MvcHtmlString RenderDropDownList(FieldModel model)
{
ISerializer serializer = new SerializeJSon();
var value = "";
var tb1 = new TagBuilder("select");
tb1.MergeAttribute("id", model.QuestionId);
tb1.MergeAttribute("name", model.QuestionId);
tb1.MergeAttributes(GetHtmlAttributes(model.HtmlAttributes));
tb1.AddCssClass("form-field");
var sb = new StringBuilder();
MatchCollection matches = RegexHelper.GetBetweenDelimiter(model.FieldValues, "{", "}");
foreach (Match match in matches)
{
var o = match; //Solution var o = match.toString();
var tb2 = new TagBuilder("option");
//Solution string newString = o.trim(new [] { "{","}"});
tb2.SetInnerText(o.ToString()); //Solution tb2.SetInnerText(newString);
sb.Append(tb2.ToString(TagRenderMode.Normal) + "\n");
}
tb1.InnerHtml = sb.ToString();
return new MvcHtmlString(tb1.ToString(TagRenderMode.Normal));
}
string newString = originalString.Trim(new[] {'{', '}'});
Can you use Replace
string somestring = somestring.Replace("{","").Replace("}","");
Alternatively, you can use StartsWith and EndsWith which will only remove from the beginning and the end of the string, for example:
string foo = "{something}";
if (foo.StartsWith("{"))
{
foo = foo.Remove(0, 1);
}
if (foo.EndsWith("}"))
{
foo = foo.Remove(foo.Length-1, 1);
}
You could use replace e.g.
string someString = "{somestring}";
string someOtherString = someString.Replace("{","").Replace("}","");
I have a dynamic String value which may contain values like this
"Apple ,Banana, , , , Mango ,Strawberry , "
I would like to filter this string like
"Apple,Banana,Mango,Strawberry".
I have tried with the following code and it works.
Is there any better approach to achieve the same in C#(.NET 2.0)?
/// <summary>
/// Convert "Comma Separated String" to "Comma Separated String"
/// </summary>
/// <param name="strWithComma">String having values separated by comma</param>
/// <returns>String separated with comma</returns>
private String CommaSeparatedString(String strWithComma)
{
String rtn = String.Empty;
List<String> newList= new List<string>();
if (String.IsNullOrEmpty(strWithComma))
{
return rtn;
}
String[] strArray = strWithComma.Split(",".ToCharArray());
if (strArray == null || strArray.Length == 0)
{
return rtn;
}
String tmpStr = String.Empty;
String separator=String.Empty;
foreach (String s in strArray)
{
if (!String.IsNullOrEmpty(s))
{
tmpStr =s.Replace(Environment.NewLine, String.Empty);
tmpStr = tmpStr.Trim();
if (!String.IsNullOrEmpty(tmpStr))
{
newList.Add(tmpStr);
}
}
}
if (newList != null && newList.Count > 0)
{
rtn = String.Join(",", newList.ToArray());
}
return rtn;
}
you can also use Regex:
string str = #"Apple ,,Banana, , , , Mango ,Strawberry , ";
string result = Regex.Replace(str, #"(\s*,\s*)+", ",").TrimEnd(',');
I believe the following should do the trick on any .NET version:
string[] TrimAll( string[] input )
{
var result = new List<string>();
foreach( var s in input )
result.Add( s.Trim() );
}
return result.ToArray();
}
var delimiters = new [] { ",", "\t", Environment.NewLine };
string result = string.Join(",", TrimAll( input.Split( delimiters, StringSplitOptions.RemoveEmptyEntries ) ) );
Edit: updated to deal with white-space, tabs and newline.
Assuming that your items do not contain spaces:
private String CommaSeparatedString(String strWithComma)
{
string[] tokens = strWithComma
.Replace(" ", "")
.Split(new char[] {','}, StringSplitOptions.RemoveEmptyEntries);
return string.Join(",", tokens);
}
Now I'm not sure if C# 2.0 accepts the new char[] {','} syntax. If not, you can define the array somewhere else (as a class private member, for example).
Here's a one-liner:
var outputString = string.Join(",", inputString.Replace(" ", string.Empty).Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries));
Regex regex = new Regex(#"\w(?:(?!,| ).)*");
var items = regex.Matches("Apple ,Banana, , , , Mango ,Strawberry , ").Cast<Match>().Select(m => m.Value);
.NET 2.0 Version
List<string> newList = new List<string>();
Regex regex = new Regex(#"\w(?:(?!,| ).)*");
string str = "Apple ,Banana, , , , Mango ,Strawberry , ";
MatchCollection matches = regex.Matches(str);
foreach (Match match in matches)
{
newList.Add(match.Value);
}
var result = Regex.Replace(strWithComma, ",+", ",").TimEnd(',');
result = Regex.Replace(result, "\s+", string.Empty);
With no regular expressions, no splits and joins, trims, etc, O(n) time. StringBuilder is a very good class to work with strings.
EDIT
If the string it doesn't end with a letter it will add a comma. So an extra TrimEnd(',') is added
string strWithComma = ",Apple ,Banana, , , , Mango ,Strawberry , \n John,";
var sb = new StringBuilder();
var addComma = false;
foreach (var c in strWithComma )
{
if (Char.IsLetter(c)) // you might want to allow the dash also: example Anne-Marie
{
addComma = true;
sb.Append(c);
}
else
{
if (addComma)
{
addComma = false;
sb.Append(',');
}
}
}
string rtn = sb.ToString().TrimEnd(',');
Warning this method will only apply for C# 3.0 or higher. Sorry guys didnt read the question well enough
This will work but it can be done much easier like:
string input = "apple,banana,, \n,test\n, ,juice";
var parts = from part in input.Split(',')
let trimmedPart = part.Replace("\n", "")
where !string.IsNullOrWhiteSpace(trimmedPart)
select trimmedPart;
string result = string.Join(",", parts);