Develop Reference

Splitting strings with multiple characters [duplicate]

This question already has answers here:
Regex.Split() on comma, space or semi-colon delimitted string
(5 answers)
Closed 6 years ago.
if (clientInfo.cf.geo_region != null)
{
List<string> geoListRegion = clientInfo.cf.geo_region.Split(new string[] { ",", ", " }, StringSplitOptions.RemoveEmptyEntries).ToList();
rs_product_hit = rs_product_hit.Where(ph => geoListRegion.Contains(ph.region));
}
I want to be able to input either "AMAC,South America" or "AMAC, South America" and split where the comma is placed with/without a space after. Unfortunately, my output is only splitting the comma without the space, giving me the correct output if the input is "AMAC,South America". What could I do to get the same result with or without the space after the comma?

Simple Workaround: changing the order of your splitting strings to new string[] { ", ", ","} will resolve the issue. You could also use string.Trim() to remove leading or trailing spaces.

You're close, but you need to do Trim()
if (clientInfo.cf.geo_region != null)
{
List<string> geoListRegion = clientInfo.cf.geo_region.Split(new string[] { ",", ", " }, StringSplitOptions.RemoveEmptyEntries).ToList();
rs_product_hit = rs_product_hit.Where(ph => geoListRegion.Contains(ph.region.Trim()));
}

Two ways:
swap the order of your splitting strings as answered by Bastian Thiede.
Regex. Remove all whitespace after commas using Regex.Replace(myString, #",\s+", ""). The benefit of using this method is that it removes any number of spaces succeeding a comma.

The "Why" Behind String.Empty at the End of a String

Background
I am working with a delimited string and was using String.Split to put each substring into an array when I noticed that the last spot in the array was "". It was throwing off my results since I was looking for a specific substring at the last index in the array and I eventually came across this post explaining all strings end with string.Empty.
Example
The following shows this behavior in action. When I split my sentence and write each substring to the console, we can see the last element is the empty string:
public class Program
{
static void Main(string[] args)
{
const string mySentence = "Hello,this,is,my,string!";
var wordArray = mySentence.Split(new[] {",", "!"}, StringSplitOptions.None);
foreach (var word in wordArray)
{
var message = word;
if (word == string.Empty) message = "Empty string";
Console.WriteLine(message);
}
Console.ReadKey();
}
}
Question & "Fix"
I get conceptually that there are empty strings between every character, but why does String behave like this even for the end of a string? It seems confusing that "ABC" is equivalent to "ABC" + "" or ABC + "" + "" + "" so why not treat the string literally as only "ABC"?
There is a "fix" around it to get the "true" substrings I wanted:
public class Program
{
static void Main(string[] args)
{
const string mySentence = "Hello,this,is,my,string!";
var wordArray = mySentence.Split(new[] {",", "!"}, StringSplitOptions.None);
var wordList = new List<string>();
wordList.AddRange(wordArray);
wordList.RemoveAt(wordList.LastIndexOf(string.Empty));
foreach (var word in wordList)
{
var message = word;
if (word == string.Empty) message = "Empty string";
Console.WriteLine(message);
}
Console.ReadKey();
}
}
But I still don't understand why the end of the string gets treated with the same behavior since there is not another character following it where an empty string would be needed. Does it serve some purpose for the compiler?

Empty strings are the 0 of strings. There are literally infinity of them everywhere.
It's only natural that "ABC" is equivalent to "ABC" + "" or ABC + "" + "" + "". Just like it's natural that 3 is equivalent to 3 + 0 or 3 + 0 + 0 + 0.
and the fact that you have an empty string after "Hello,this,is,my,string!".Split('!')" does mean something. It means that your string ended with a "!"

This is happening because you are using StringSplitOptions.None while one of your delimiter values occurs at the end of the string. The entire purpose of that option is to create the behavior you are observing: it splits a string containing N delimiters into exactly N + 1 pieces.
To see the behavior you want, use StringSplitOptions.RemoveEmptyEntries:
var wordArray = mySentence.Split(new[] {",", "!"}, StringSplitOptions.RemoveEmptyEntries);
As for why you are seeing what you're seeing. The behavior StringSplitOptions.None is to find all the places where the delimiters are in the input string and return an array of each piece before and after the delimiters. This could be useful, for example, if you're parsing a string that you know to have exactly N parts, but where some of them could be blank. So for example, splitting the following on a comma delimiter, they would each yield exactly 3 parts:
a,b,c
a,b,
a,,c
a,,
,b,c
,b,
,,c
,,
If you want to allow empty values between delimiters, but not at the beginning or end, you can strip off delimiters at the beginning or end of the string before splitting:
var wordArray = Regex
.Replace(mySentence, "^[,!]|[,!]$", "")
.Split(new[] {",", "!"}, StringSplitOptions.None);

"" is the gap in-between each letter of Hello,this,is,my,string! So when the string is split by , and ! the result is Hello, this, is, my, string, "". The "" being the empty character between the end of the string and !.
If you replaced "" with a visible character (say #) your string would look like this #H#e#l#l#o#,#t#h#i#s#,#i#s#,#m#y#,#s#t#r#i#n#g#!#.

Splitting string with dots and spaces [duplicate]

This question already has answers here:
Regex split string but keep separators
(2 answers)
Closed 7 years ago.
Let's say I have the following string: "This is a test. Haha.". I want to split it so that it becomes these there lines:
Hey.
This is a test.
Haha.
(Note that the space after the dot is preserved).
I tried to split the string using the Split method, and split by the dot, but it returns 3 new strings with the space before the string, and it removes the dots. I want to keep the space after the dot and keep the space.
How can I achieve this?
EDIT: I found a workaround, but I'm sure there's a simpler way:
string a = "Hey. This is a test. Haha.";
string[] splitted = a.Split('.');
foreach(string b in splitted)
{
if (b.Length < 3)
{
continue;
}
string f = b.Remove(0, 1);
Console.WriteLine(f + ". ");
}

I can't test this but due to the post of Darin Dimitrov :
string input = "Hey. This is a test. Haha.";
string result = input.Replace(". ", ".\n");

How to remove spaces and newlines in a string [duplicate]

This question already has answers here:
Fastest way to remove white spaces in string
(13 answers)
Closed 9 years ago.
sorry if they are not very practical for C # Asp.Net, I hope to make me understand
I have this situation
string content = ClearHTMLTags(HttpUtility.HtmlDecode(e.Body));
content=content.Replace("\r\n", "");
content=content.Trim();
((Post)sender).Description = content + "...";
I would make sure that the string does not contain content nor spaces (Trim) and neither carriage return with line feed, I'm using the above code inserted but it does not work great either
any suggestions??
Thank you very much
Fabry

You can remove all whitespaces with this regex
content = Regex.Replace(content, #"\s+", string.Empty);
what are whitespace characters from MSDN.
Btw you are mistaking Trim with removing spaces, in fact it's only removing spaces at the begining and at the end of string. If you want to replace all spaces and carige returns use my regex.

this should do it
String text = #"hdjhsjhsdcj/sjksdc\t\r\n asdf";
string[] charactersToReplace = new string[] { #"\t", #"\n", #"\r", " " };
foreach (string s in charactersToReplace)
{
text = text.Replace(s, "");
}

simple change only you missed # symbol
string content = ClearHTMLTags(HttpUtility.HtmlDecode(e.Body));
content=content.Replace(#"\r\n", "");
content=content.Trim();
((Post)sender).Description = content + "...";

Insert space between characters

I have a string,
string aString = "a,aaa,aaaa,aaaaa,,,,,";
Where i want to insert to a List..But when i do using the following method,
List<string> aList = new List<string>();
aList.AddRange(aString.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries));
MessageBox.Show(aList.Count.ToString());
I get the count as only 4, But there are actually 8 elements even the final characters in between the (,) sign is blank.
But if i pass the string as shown below,
string aString = "a,aaa,aaaa,aaaaa, , , , ,";
It will be shown as 8 elements..Please help me on this, the default way thw program retrieves the string is like so,
a,aaa,aaaa,aaaaa,,,,,
Please help on this one, It would be great if i could add spaces to the empty area or any other way so that i could add all these characters in between (,) sign to the list.. even the blank areas. Thank you :)

Don't use StringSplitOptions.RemoveEmptyEntries
string aString = "a,aaa,aaaa,aaaaa,,,,,";
var newStr = String.Join(", ", aString.Split(','));

I think you must remove StringSplitOptions.RemoveEmptyEntries
aList.AddRange(aString.Replace(",,", ", ,").Split(new string[] { "," }));

You can just Replace the space before split it.
aList.AddRange(aString.Replace(" ", "").Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries));