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My Regex.Split with '\n' takes up two spaces instead of 1

I need to split my text into each word, space, and new line.
Although the words and spaces are properly working, the \n is taking up two spaces only if it's not after a word.
Example: "\nTest\nword", here, the first \n takes up two spaces while the second one takes up one.
How would I write the proper regex?
My code:
string delimiterChars = "([ \r\n])";
wordArray = Regex.Split(myTexy, delimiterChars);
For context, I am using Unity.
Input: enter image description here
Output: enter image description here
On the output of the picture: The first element is empty and the second is \n here. I don't want the empty element.

Regex.Split will always produce empty items where the matches are consecutive, or when they are at the start/end of string.
Instead, you can use a matching and extracting approach:
string delimiterChars = "[^ \r\n]+|[ \r\n]";
string[] wordArray = Regex.Matches(myTexy, delimiterChars)
.Cast<Match>()
.Select(m => m.Value)
.ToArray();
The [^ \r\n]+|[ \r\n] regex matches one or more chars other than a space, CR and LF, or a space, CR or an LF char.

You can use regular expressions to remove leading delimiter characters.
var myTexy = "\nTest\nword";
string delimiterChars = "([ \r\n])";
myTexy = Regex.Replace(myTexy, "^" + delimiterChars, "");
var wordArray = Regex.Split(myTexy, delimiterChars);
The "^" regex option says only look for these characters at the beginning of the string.
Also, just so you are aware the behavior you are seeing is intended and is documented here:
If a match is found at the beginning or the end of the input string,
an empty string is included at the beginning or the end of the
returned array.

Let me know if this is what you are looking for -
String text = "\nTest\nword";
string[] words = Regex.Split(text, #"(\n+)");
Output -

Try this :-
string myStr = "This is test text";
wordArray = myStr.Split(new char[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
Output:

Regex - Removing specific characters before the final occurance of #

So, I'm trying to remove certain characters [.&#] before the final occurance of an #, but after that final #, those characters should be allowed.
This is what I have so far.
string pattern = #"\.|\&|\#(?![^#]+$)|[^a-zA-Z#]";
string input = "username#middle&something.else#company.com";
// input, pattern, replacement
string result = Regex.Replace(input, pattern, string.Empty);
Console.WriteLine(result);
Output: usernamemiddlesomethingelse#companycom
This currently removes all occurances of the specified characters, apart from the final #. I'm not sure how to get this to work, help please?

You may use
[.&#]+(?=.*#)
Or, equivalent [.&#]+(?![^#]*$). See the regex demo.
Details
[.&#]+ - 1 or more ., & or # chars
(?=.*#) - followed with any 0+ chars (other than LF) as many as possible and then a #.
See the C# demo:
string pattern = #"[.&#]+(?=.*#)";
string input = "username#middle&something.else#company.com";
string result = Regex.Replace(input, pattern, string.Empty);
Console.WriteLine(result);
// => usernamemiddlesomethingelse#company.com

Just a simple solution (and alternative to complex regex) using Substring and LastIndexOf:
string pattern = #"[.#&]";
string input = "username#middle&something.else#company.com";
string inputBeforeLastAt = input.Substring(0, input.LastIndexOf('#'));
// input, pattern, replacement
string result = Regex.Replace(inputBeforeLastAt, pattern, string.Empty) + input.Substring(input.LastIndexOf('#'));
Console.WriteLine(result);
Try it with this fiddle.

How to remove multiple first characters using regex?

I have string string A = "... :-ggw..-:p";
using regex: string B = Regex.Replace(A, #"^\.+|:|-|", "").Trim();
My Output isggw..p.
What I want is ggw..-:p.
Thanks

You may use a character class with your symbols and whitespace shorthand character class:
string B = Regex.Replace(A, #"^[.:\s-]+", "");
See the regex demo
Details
^ - start of string
[.:\s-]+ - one or more characters defined in the character class.
Note that there is no need escaping . inside [...]. The - does not have to be escaped since it is at the end of the character class.

A regex isn't necessary if you only want to trim specific characters from the start of a string. System.String.TrimStart() will do the job:
var source = "... :-ggw..-:p";
var charsToTrim = " .:-".ToCharArray();
var result = source.TrimStart(charsToTrim);
Console.WriteLine(result);
// Result is 'ggw..-:p'

Replace Unicode character "�" with a space

I'm a doing an massive uploading of information from a .csv file and I need replace this character non ASCII "�" for a normal space, " ".
The character "�" corresponds to "\uFFFD" for C, C++, and Java, which it seems that it is called REPLACEMENT CHARACTER. There are others, such as spaces type like U+FEFF, U+205F, U+200B, U+180E, and U+202F in the C# official documentation.
I'm trying do the replace this way:
public string Errors = "";
public void test(){
string textFromCsvCell = "";
string validCharacters = "^[0-9A-Za-z().:%-/ ]+$";
textFromCsvCell = "This is my text from csv file"; //All spaces aren't normal space " "
string cleaned = textFromCsvCell.Replace("\uFFFD", "\"")
if (Regex.IsMatch(cleaned, validCharacters ))
//All code for insert
else
Errors=cleaned;
//print Errors
}
The test method shows me this text:
"This is my�texto from csv file"
I try some solutions too:
Trying solution 1: Using Trim
Regex.Replace(value.Trim(), #"[^\S\r\n]+", " ");
Try solution 2: Using Replace
System.Text.RegularExpressions.Regex.Replace(str, #"\s+", " ");
Try solution 3: Using Trim
String.Trim(new char[]{'\uFEFF', '\u200B'});
Try solution 4: Add [\S\r\n] to validCharacters
string validCharacters = "^[\S\r\n0-9A-Za-z().:%-/ ]+$";
Nothing works.
How can I replace it?
Sources:
Unicode Character 'REPLACEMENT CHARACTER' (U+FFFD)
Trying to replace all white space with a single space
Strip the byte order mark from string in C#
Remove extra whitespaces, but keep new lines using a regular expression in C#
EDITED
This is the original string:
"SYSTEM OF MONITORING CONTINUES OF GLUCOSE"
in 0x... notation
SYSTEM OF0xA0MONITORING CONTINUES OF GLUCOSE
Solution
Go to the Unicode code converter. Look at the conversions and do the replace.
In my case, I do a simple replace:
string value = "SYSTEM OF MONITORING CONTINUES OF GLUCOSE";
//value contains non-breaking whitespace
//value is "SYSTEM OF�MONITORING CONTINUES OF GLUCOSE"
string cleaned = "";
string pattern = #"[^\u0000-\u007F]+";
string replacement = " ";
Regex rgx = new Regex(pattern);
cleaned = rgx.Replace(value, replacement);
if (Regex.IsMatch(cleaned,"^[0-9A-Za-z().:<>%-/ ]+$"){
//all code for insert
else
//Error messages
This expression represents all possible spaces: space, tab, page break, line break and carriage return
[ \f\n\r\t\v​\u00a0\u1680​\u180e\u2000​\u2001\u2002​\u2003\u2004​\u2005\u2006​\u2007\u2008​\u2009\u200a​\u2028\u2029​​\u202f\u205f​\u3000]
References
Regular expressions (MDN)

Using String.Replace:
Use a simple String.Replace().
I've assumed that the only characters you want to remove are the ones you've mentioned in the question: � and you want to replace them by a normal space.
string text = "imp�ortant";
string cleaned = text.Replace('\u00ef', ' ')
.Replace('\u00bf', ' ')
.Replace('\u00bd', ' ');
// Returns 'imp ortant'
Or using Regex.Replace:
string cleaned = Regex.Replace(text, "[\u00ef\u00bf\u00bd]", " ");
// Returns 'imp ortant'
Try it out: Dotnet Fiddle

Define a range of ASCII characters, and replace anything that is not within that range.
We want to find only Unicode characters, so we will match on a Unicode character and replace.
Regex.Replace("This is my te\uFFFDxt from csv file", #"[^\u0000-\u007F]+", " ")
The above pattern will match anything that is not ^ in the set [ ] of this range \u0000-\u007F (ASCII characters (everything past \u007F is Unicode)) and replace it with a space.
Result
This is my te xt from csv file
You can adjust the range provided \u0000-\u007F as needed to expand the range of allowed characters to suit your needs.

If you just want ASCII then try the following:
var ascii = new ASCIIEncoding();
byte[] encodedBytes = ascii.GetBytes(text);
var cleaned = ascii.GetString(encodedBytes).Replace("?", " ");

Using Regex Replace instead of String Replace

I am not clued up on Regex as much as I should be, so this may seem like a silly question.
I am splitting a string into a string[] with .Split(' ').
The purpose is to check the words, or replace any.
The problem I'm having now, is that for the word to be replaces, it has to be an exact match, but with the way I'm splitting it, there might be a ( or [ with the split word.
So far, to counter that, I'm using something like this:
formattedText.Replace(">", "> ").Replace("<", " <").Split(' ').
This works fine for now, but I want to incorporate more special chars, such as [;\\/:*?\"<>|&'].
Is there a quicker way than the method of my replacing, such as Regex? I have a feeling my route is far from the best answer.
EDIT
This is an (example) string
would be replaced to
This is an ( example ) string

If you want to replace whole words, you can do that with a regular expression like this.
string text = "This is an example (example) noexample";
string newText = Regex.Replace(text, #"\bexample\b", "!foo!");
newText will contain "This an !foo! (!foo!) noexample"
The key here is that the \b is the word break metacharacter. So it will match at the beginning or end of a line, and the transitions between word characters (\w) and non-word characters (\W). The biggest difference between it and using \w or \W is that those won't match at the beginning or end of lines.

I thing this is the right thing you want
if you want these -> ;\/:*?"<>|&' symbols to replace
string input = "(exam;\\/:*?\"<>|&'ple)";
Regex reg = new Regex("[;\\/:*?\"<>|&']");
string result = reg.Replace(input, delegate(Match m)
{
return " " + m.Value + " ";
});
if you want to replace all characters except a-zA-Z0-9_
string input = "(example)";
Regex reg = new Regex(#"\W");
string result = reg.Replace(input, delegate(Match m)
{
return " " + m.Value + " ";
});