Develop Reference

Replacing first part of string by another

I need to replace multiple file names in a folder. Here is one of the files:
Abc.CDE.EFG
I need to replace the first part of the string before the dot ("ABC") and replace it with: "zef".
Any ideas? I found this but it takes out the dot and not sure how to add the "zef".
var input = _FileInfo.ToString();
var output = input.Substring(input.IndexOf(".").Trim())

Since the question is tagged with regex, you can use a regular expression like so:
var input = "abc.def.efg";
var pattern = "^[^\\.]+";
var replacement = "zef";
var rgx = new Regex(pattern);
var output = rgx.Replace(input, replacement);
Source: https://msdn.microsoft.com/en-us/library/xwewhkd1(v=vs.110).aspx

You are almost there, try:
string myString = "Abc.CDE.EFG";
//This splits your string into an array with 3 items
//"Abc", "CDE" and "EFG"
var stringArray = myString.Split('.');
//Now modify the first item by changing it to "zef"
stringArray[0] = "zef";
//Then we rebuild the string by joining the array together
//delimiting each group by a period
string newString = string.Join(".", stringArray);
With this solution you can independently access any of the "blocks" just by referencing the array by index.
Fiddle here

Try this:
var input = _FileInfo.ToString();
var output = "zef" + input.Substring(input.IndexOf("."));

If you know the length of the first string , you can replace mentioning number of characters starting from position until the length you want to replace else.
string s = "Abc.CDE.EFG";
string [] n = s.Split('.');
n[0] = "ZEF";
string p = string.Join(".",n);
Console.WriteLine(p);
}

extracting strings between 2 chars - all occurrences

I would like to do something like this:
My string example: "something;123:somethingelse;156:somethingelse2;589:somethingelse3"
I would like to get an array with values extracted from the string example. These values lies between ";" and ":" : 123, 156, 589
I have tried this, but I do not know how to iterate to get all occurrences:
string str = stringExample.Split(';', ':')[1];
string[i] arr = str;
Thank you for helping me.

LINQ is your friend here, something like this would do:
str.Split(';').Select(s => s.Split(':')[0]).Skip(1)

I would work with named groups:
string stringExample = "something;123:somethingelse;156:somethingelse2;589:somethingelse3";
Regex r = new Regex(";(?<digit>[0-9]+):");
foreach (Match item in r.Matches(stringExample))
{
var digit = item.Groups["digit"].Value;
}

You can use a regular expression like this:
Regex r = new Regex(#";(\d+):");
string s = "something;123:somethingelse;156:somethingelse2;589:somethingelse3";
foreach(Match m in r.Matches(s))
Console.WriteLine(m.Groups[1]);
;(\d+): matches one or more digits standing between ; and : and Groups[1] selects the content inside the brackest, ergo the digits.
Output:
123
156
589
To get these strings into an array use:
string[] numberStrings = r.Matches(s).OfType<Match>()
.Select(m => m.Groups[1].Value)
.ToArray();

So you want to extract all 3 numbers, you could use this approach:
string stringExample = "something;123:somethingelse;156:somethingelse2;589:somethingelse3";
string[] allTokens = stringExample.Split(';', ':'); // remove [1] since you want the whole array
string[] allNumbers = allTokens.Where(str => str.All(Char.IsDigit)).ToArray();
Result is:
allNumbers {string[3]} string[]
[0] "123" string
[1] "156" string
[2] "589" string

This sounds like a perfect case for a regular expression.
var sample = "something;123:somethingelse;156:somethingelse2;589:somethingelse3";
var regex = new Regex(#"(?<=;)(\d+)(?=:)");
var matches = regex.Matches(sample);
var array = matches.Cast<Match>().Select(m => m.Value).ToArray();

Get values between curly braces c#

I never used regex before. I was abel to see similar questions in forum but not exactly what im looking for
I have a string like following. need to get the values between curly braces
Ex: "{name}{name#gmail.com}"
And i Need to get the following splitted strings.
name and name#gmail.com
I tried the following and it gives me back the same string.
string s = "{name}{name#gmail.com}";
string pattern = "({})";
string[] result = Regex.Split(s, pattern);

Use Matches of Regex rather than Split to accomplish this easily:
string input = "{name}{name#gmail.com}";
var regex = new Regex("{(.*?)}");
var matches = regex.Matches(input);
foreach (Match match in matches) //you can loop through your matches like this
{
var valueWithoutBrackets = match.Groups[1].Value; // name, name#gmail.com
var valueWithBrackets = match.Value; // {name}, {name#gmail.com}
}

Is using regex a must? In this particular example I would write:
s.Split(new char[] { '{', '}' }, StringSplitOptions.RemoveEmptyEntries)

here you go
string s = "{name}{name#gmail.com}";
s = s.Substring(1, s.Length - 2);// remove first and last characters
string pattern = "}{";// split pattern "}{"
string[] result = Regex.Split(s, pattern);
or
string s = "{name}{name#gmail.com}";
s = s.TrimStart('{');
s = s.TrimEnd('}');
string pattern = "}{";
string[] result = Regex.Split(s, pattern);

Extract digit in a string

I have a list of string
goal0=1234.4334abc12423423
goal1=-234234
asdfsdf
I want to extract the number part from string that start with goal,
in the above case is
1234.4334, -234234
(if two fragments of digit get the first one)
how should i do it easily?
Note that "goal0=" is part of the string, goal0 is not a variable.
Therefore I would like to have the first digit fragment that come after "=".

You can do the following:
string input = "goal0=1234.4334abc12423423";
input = input.Substring(input.IndexOf('=') + 1);
IEnumerable<char> stringQuery2 = input.TakeWhile(c => Char.IsDigit(c) || c=='.' || c=='-');
string result = string.Empty;
foreach (char c in stringQuery2)
result += c;
double dResult = double.Parse(result);

Try this
string s = "goal0=-1234.4334abc12423423";
string matches = Regex.Match(s, #"(?<=^goal\d+=)-?\d+(\.\d+)?").Value;
The regex says
(?<=^goal\d+=) - A positive look behind which means look back and make sure goal(1 or more number)= is at the start of the string, but dont make it part of the match
-? - A minus sign which is optional (the ? means 1 or more)
\d+ - One or more digits
(\.\d+)? - A decimal point followed by 1 or more digits which is optional
This will work if your string contains multiple decimal points as well as it will only take the first set of numbers after the first decimal point if there are any.

Use a regex for extracting:
x = Regex.Match(string, #"\d+").Value;
Now convert the resulting string to the number by using:
finalNumber = Int32.Parse(x);

Please try this:
string sample = "goal0=1234.4334abc12423423goal1=-234234asdfsdf";
Regex test = new Regex(#"(?<=\=)\-?\d*(\.\d*)?", RegexOptions.Singleline);
MatchCollection matchlist = test.Matches(sample);
string[] result = new string[matchlist.Count];
if (matchlist.Count > 0)
{
for (int i = 0; i < matchlist.Count; i++)
result[i] = matchlist[i].Value;
}
Hope it helps.
I didn't get the question at first. Sorry, but it works now.

I think this simple expression should work:
Regex.Match(string, #"\d+")

You can use the old VB Val() function from C#. That will extract a number from the front of a string, and it's already available in the framework:
result0 = Microsoft.VisualBasic.Conversion.Val(goal0);
result1 = Microsoft.VisualBasic.Conversion.Val(goal1);

string s = "1234.4334abc12423423";
var result = System.Text.RegularExpressions.Regex.Match(s, #"-?\d+");

List<String> list = new List<String>();
list.Add("goal0=1234.4334abc12423423");
list.Add("goal1=-23423");
list.Add("asdfsdf");
Regex regex = new Regex(#"^goal\d+=(?<GoalNumber>-?\d+\.?\d+)");
foreach (string s in list)
{
if(regex.IsMatch(s))
{
string numberPart = regex.Match(s).Groups["GoalNumber"];
// do something with numberPart
}
}

Remove String After Determinate String

I need to remove certain strings after another string within a piece of text.
I have a text file with some URLs and after the URL there is the RESULT of an operation. I need to remove the RESULT of the operation and leave only the URL.
Example of text:
http://website1.com/something Result: OK(registering only mode is on)
http://website2.com/something Result: Problems registered 100% (SOMETHING ELSE) Other Strings;
http://website3.com/something Result: error: "Âíèìàíèå, îáíàðóæåíà îøèáêà - Ìåñòî æèòåëüñòâà ñîäåðæèò íåäîïóñòèìûå ê
I need to remove all strings starting from Result: so the remaining strings have to be:
http://website1.com/something
http://website2.com/something
http://website3.com/something
Without Result: ........
The results are generated randomly so I don't know exactly what there is after RESULT:

One option is to use regular expressions as per some other answers. Another is just IndexOf followed by Substring:
int resultIndex = text.IndexOf("Result:");
if (resultIndex != -1)
{
text = text.Substring(0, resultIndex);
}
Personally I tend to find that if I can get away with just a couple of very simple and easy to understand string operations, I find that easier to get right than using regex. Once you start going into real patterns (at least 3 of these, then one of those) then regexes become a lot more useful, of course.

string input = "Action2 Result: Problems registered 100% (SOMETHING ELSE) Other Strings; ";
string pattern = "^(Action[0-9]*) (.*)$";
string replacement = "$1";
Regex rgx = new Regex(pattern);
string result = rgx.Replace(input, replacement);
You use $1 to keep the match ActionXX.

Use Regex for this.
Example:
var r = new System.Text.RegularExpressions.Regex("Result:(.)*");
var result = r.Replace("Action Result:1231231", "");
Then you will have "Action" in the result.

You can try with this code - by using string.Replace
var pattern = "Result:";
var lineContainYourValue = "jdfhkjsdfhsdf Result:ljksdfljh"; //I want replace test
lineContainYourValue.Replace(pattern,"");

Something along the lines of this perhaps?
string line;
using ( var reader = new StreamReader ( File.Open ( #"C:\temp\test.txt", FileMode.Open ) ) )
using ( var sw = new StreamWriter(File.Open( #"C:\Temp\test.edited.txt", FileMode.CreateNew ) ))
while ( (line = reader.ReadLine()) != null )
if(!line.StartsWith("Result:")) sw.WriteLine(line);

You can use RegEx for this kind of processing.
using System.Text.RegularExpressions;
private string ParseString(string originalString)
{
string pattern = ".*(?=Result:.*)";
Match match = Regex.Match(originalString, pattern);
return match.Value;
}

A Linq approach:
IEnumerable<String> result = System.IO.File
.ReadLines(path)
.Where(l => l.StartsWith("Action") && l.Contains("Result"))
.Select(l => l.Substring(0, l.IndexOf("Result")));

Given your current example, where you want only the website, regex match the spaces.
var fileLine = "http://example.com/sub/ random text";
Regex regexPattern = new Regex("(.*?)\\s");
var websiteMatch = regexPattern.Match(fileLine).Groups[1].ToString();
Debug.Print("!" + websiteMatch + "!");
Repeating for each line in your text file. Regex explained: .* matches anything, ? makes the match ungreedy, (brackets) puts the match into a group, \\s matches whitespace.