How can I replace multiple spaces in a string with only one space in C#?
Example:
1 2 3 4 5
would be:
1 2 3 4 5
I like to use:
myString = Regex.Replace(myString, #"\s+", " ");
Since it will catch runs of any kind of whitespace (e.g. tabs, newlines, etc.) and replace them with a single space.
string sentence = "This is a sentence with multiple spaces";
RegexOptions options = RegexOptions.None;
Regex regex = new Regex("[ ]{2,}", options);
sentence = regex.Replace(sentence, " ");
string xyz = "1 2 3 4 5";
xyz = string.Join( " ", xyz.Split( new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries ));
I think Matt's answer is the best, but I don't believe it's quite right. If you want to replace newlines, you must use:
myString = Regex.Replace(myString, #"\s+", " ", RegexOptions.Multiline);
Another approach which uses LINQ:
var list = str.Split(' ').Where(s => !string.IsNullOrWhiteSpace(s));
str = string.Join(" ", list);
It's much simpler than all that:
while(str.Contains(" ")) str = str.Replace(" ", " ");
Regex can be rather slow even with simple tasks. This creates an extension method that can be used off of any string.
public static class StringExtension
{
public static String ReduceWhitespace(this String value)
{
var newString = new StringBuilder();
bool previousIsWhitespace = false;
for (int i = 0; i < value.Length; i++)
{
if (Char.IsWhiteSpace(value[i]))
{
if (previousIsWhitespace)
{
continue;
}
previousIsWhitespace = true;
}
else
{
previousIsWhitespace = false;
}
newString.Append(value[i]);
}
return newString.ToString();
}
}
It would be used as such:
string testValue = "This contains too much whitespace."
testValue = testValue.ReduceWhitespace();
// testValue = "This contains too much whitespace."
myString = Regex.Replace(myString, " {2,}", " ");
For those, who don't like Regex, here is a method that uses the StringBuilder:
public static string FilterWhiteSpaces(string input)
{
if (input == null)
return string.Empty;
StringBuilder stringBuilder = new StringBuilder(input.Length);
for (int i = 0; i < input.Length; i++)
{
char c = input[i];
if (i == 0 || c != ' ' || (c == ' ' && input[i - 1] != ' '))
stringBuilder.Append(c);
}
return stringBuilder.ToString();
}
In my tests, this method was 16 times faster on average with a very large set of small-to-medium sized strings, compared to a static compiled Regex. Compared to a non-compiled or non-static Regex, this should be even faster.
Keep in mind, that it does not remove leading or trailing spaces, only multiple occurrences of such.
This is a shorter version, which should only be used if you are only doing this once, as it creates a new instance of the Regex class every time it is called.
temp = new Regex(" {2,}").Replace(temp, " ");
If you are not too acquainted with regular expressions, here's a short explanation:
The {2,} makes the regex search for the character preceding it, and finds substrings between 2 and unlimited times.
The .Replace(temp, " ") replaces all matches in the string temp with a space.
If you want to use this multiple times, here is a better option, as it creates the regex IL at compile time:
Regex singleSpacify = new Regex(" {2,}", RegexOptions.Compiled);
temp = singleSpacify.Replace(temp, " ");
You can simply do this in one line solution!
string s = "welcome to london";
s.Replace(" ", "()").Replace(")(", "").Replace("()", " ");
You can choose other brackets (or even other characters) if you like.
no Regex, no Linq... removes leading and trailing spaces as well as reducing any embedded multiple space segments to one space
string myString = " 0 1 2 3 4 5 ";
myString = string.Join(" ", myString.Split(new char[] { ' ' },
StringSplitOptions.RemoveEmptyEntries));
result:"0 1 2 3 4 5"
// Mysample string
string str ="hi you are a demo";
//Split the words based on white sapce
var demo= str .Split(' ').Where(s => !string.IsNullOrWhiteSpace(s));
//Join the values back and add a single space in between
str = string.Join(" ", demo);
// output: string str ="hi you are a demo";
Consolodating other answers, per Joel, and hopefully improving slightly as I go:
You can do this with Regex.Replace():
string s = Regex.Replace (
" 1 2 4 5",
#"[ ]{2,}",
" "
);
Or with String.Split():
static class StringExtensions
{
public static string Join(this IList<string> value, string separator)
{
return string.Join(separator, value.ToArray());
}
}
//...
string s = " 1 2 4 5".Split (
" ".ToCharArray(),
StringSplitOptions.RemoveEmptyEntries
).Join (" ");
I just wrote a new Join that I like, so I thought I'd re-answer, with it:
public static string Join<T>(this IEnumerable<T> source, string separator)
{
return string.Join(separator, source.Select(e => e.ToString()).ToArray());
}
One of the cool things about this is that it work with collections that aren't strings, by calling ToString() on the elements. Usage is still the same:
//...
string s = " 1 2 4 5".Split (
" ".ToCharArray(),
StringSplitOptions.RemoveEmptyEntries
).Join (" ");
Many answers are providing the right output but for those looking for the best performances, I did improve Nolanar's answer (which was the best answer for performance) by about 10%.
public static string MergeSpaces(this string str)
{
if (str == null)
{
return null;
}
else
{
StringBuilder stringBuilder = new StringBuilder(str.Length);
int i = 0;
foreach (char c in str)
{
if (c != ' ' || i == 0 || str[i - 1] != ' ')
stringBuilder.Append(c);
i++;
}
return stringBuilder.ToString();
}
}
Use the regex pattern
[ ]+ #only space
var text = Regex.Replace(inputString, #"[ ]+", " ");
I know this is pretty old, but ran across this while trying to accomplish almost the same thing. Found this solution in RegEx Buddy. This pattern will replace all double spaces with single spaces and also trim leading and trailing spaces.
pattern: (?m:^ +| +$|( ){2,})
replacement: $1
Its a little difficult to read since we're dealing with empty space, so here it is again with the "spaces" replaced with a "_".
pattern: (?m:^_+|_+$|(_){2,}) <-- don't use this, just for illustration.
The "(?m:" construct enables the "multi-line" option. I generally like to include whatever options I can within the pattern itself so it is more self contained.
I can remove whitespaces with this
while word.contains(" ") //double space
word = word.Replace(" "," "); //replace double space by single space.
word = word.trim(); //to remove single whitespces from start & end.
Without using regular expressions:
while (myString.IndexOf(" ", StringComparison.CurrentCulture) != -1)
{
myString = myString.Replace(" ", " ");
}
OK to use on short strings, but will perform badly on long strings with lots of spaces.
try this method
private string removeNestedWhitespaces(char[] st)
{
StringBuilder sb = new StringBuilder();
int indx = 0, length = st.Length;
while (indx < length)
{
sb.Append(st[indx]);
indx++;
while (indx < length && st[indx] == ' ')
indx++;
if(sb.Length > 1 && sb[0] != ' ')
sb.Append(' ');
}
return sb.ToString();
}
use it like this:
string test = removeNestedWhitespaces("1 2 3 4 5".toCharArray());
Here is a slight modification on Nolonar original answer.
Checking if the character is not just a space, but any whitespace, use this:
It will replace any multiple whitespace character with a single space.
public static string FilterWhiteSpaces(string input)
{
if (input == null)
return string.Empty;
var stringBuilder = new StringBuilder(input.Length);
for (int i = 0; i < input.Length; i++)
{
char c = input[i];
if (i == 0 || !char.IsWhiteSpace(c) || (char.IsWhiteSpace(c) &&
!char.IsWhiteSpace(strValue[i - 1])))
stringBuilder.Append(c);
}
return stringBuilder.ToString();
}
How about going rogue?
public static string MinimizeWhiteSpace(
this string _this)
{
if (_this != null)
{
var returned = new StringBuilder();
var inWhiteSpace = false;
var length = _this.Length;
for (int i = 0; i < length; i++)
{
var character = _this[i];
if (char.IsWhiteSpace(character))
{
if (!inWhiteSpace)
{
inWhiteSpace = true;
returned.Append(' ');
}
}
else
{
inWhiteSpace = false;
returned.Append(character);
}
}
return returned.ToString();
}
else
{
return null;
}
}
Mix of StringBuilder and Enumerable.Aggregate() as extension method for strings:
using System;
using System.Linq;
using System.Text;
public static class StringExtension
{
public static string CondenseSpaces(this string s)
{
return s.Aggregate(new StringBuilder(), (acc, c) =>
{
if (c != ' ' || acc.Length == 0 || acc[acc.Length - 1] != ' ')
acc.Append(c);
return acc;
}).ToString();
}
public static void Main()
{
const string input = " (five leading spaces) (five internal spaces) (five trailing spaces) ";
Console.WriteLine(" Input: \"{0}\"", input);
Console.WriteLine("Output: \"{0}\"", StringExtension.CondenseSpaces(input));
}
}
Executing this program produces the following output:
Input: " (five leading spaces) (five internal spaces) (five trailing spaces) "
Output: " (five leading spaces) (five internal spaces) (five trailing spaces) "
Old skool:
string oldText = " 1 2 3 4 5 ";
string newText = oldText
.Replace(" ", " " + (char)22 )
.Replace( (char)22 + " ", "" )
.Replace( (char)22 + "", "" );
Assert.That( newText, Is.EqualTo( " 1 2 3 4 5 " ) );
You can create a StringsExtensions file with a method like RemoveDoubleSpaces().
StringsExtensions.cs
public static string RemoveDoubleSpaces(this string value)
{
Regex regex = new Regex("[ ]{2,}", RegexOptions.None);
value = regex.Replace(value, " ");
// this removes space at the end of the value (like "demo ")
// and space at the start of the value (like " hi")
value = value.Trim(' ');
return value;
}
And then you can use it like this:
string stringInput =" hi here is a demo ";
string stringCleaned = stringInput.RemoveDoubleSpaces();
I looked over proposed solutions, could not find the one that would handle mix of white space characters acceptable for my case, for example:
Regex.Replace(input, #"\s+", " ") - it will eat your line breaks, if they are mixed with spaces, for example \n \n sequence will be replaced with
Regex.Replace(source, #"(\s)\s+", "$1") - it will depend on whitespace first character, meaning that it again might eat your line breaks
Regex.Replace(source, #"[ ]{2,}", " ") - it won't work correctly when there's mix of whitespace characters - for example "\t \t "
Probably not perfect, but quick solution for me was:
Regex.Replace(input, #"\s+",
(match) => match.Value.IndexOf('\n') > -1 ? "\n" : " ", RegexOptions.Multiline)
Idea is - line break wins over the spaces and tabs.
This won't handle windows line breaks correctly, but it would be easy to adjust to work with that too, don't know regex that well - may be it is possible to fit into single pattern.
The following code remove all the multiple spaces into a single space
public string RemoveMultipleSpacesToSingle(string str)
{
string text = str;
do
{
//text = text.Replace(" ", " ");
text = Regex.Replace(text, #"\s+", " ");
} while (text.Contains(" "));
return text;
}
Related
I was trying to remove spaces before sentence ending but had no success. I was thinking of doing it with Split function but it didn't go well. The only thing I succeeded at was adding spaces after sentence ending. Here is my code:
static void Main(string[] args)
{
System.Windows.Forms.OpenFileDialog dlgOpen = new System.Windows.Forms.OpenFileDialog();
if (dlgOpen.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
StreamReader sr = new StreamReader(dlgOpen.FileName);
string dat1 = sr.ReadToEnd();
string dat2 = Path.GetDirectoryName(dlgOpen.FileName);
string dat3 = Path.GetFileNameWithoutExtension(dlgOpen.FileName);
string dat4 = Path.GetExtension(dlgOpen.FileName);
dat2 = dat2 + "/" + dat3 + "_norm" + dat4;
sz1(ref dat1);
Console.Write(dat1);
StreamWriter sw = new StreamWriter(dat2, false);
sw.WriteLine(dat1);
sw.Flush();
sw.Close();
Console.ReadLine();
}
}
static void sz1(ref string dat1)
{
char[] ArrayCharacters = { '.', ':', ',', ';', '!', '?' };
int i = -1;
dat1 = dat1.Trim();
for (int k = 0; k < dat1.Length; k++)
{
dat1 = dat1.Replace(" ", " ");
}
do
{
i = dat1.IndexOfAny(ArrayCharacters, i + 1);
if (i != -1)
{
dat1 = dat1.Insert((i + 1), " ");
dat1 = dat1.Replace(" ", " ");
}
} while (i != -1);
do
{
i = dat1.IndexOfAny(ArrayCharacters, i + 1);
if (i != -1)
{
dat1 = dat1.Insert((i - 1), " ");
dat1 = dat1.Replace(" ", " ");
dat1 = dat1.Remove(i - 1, 1);
}
} while (i != -1);
}
One option is using regex:
string pattern = "\\s+$";
string replacement = "";
Regex rgx = new Regex(pattern);
string result = rgx.Replace(dat1, replacement);
If you're just learning programming, then one solution that you should be familiar with is to use a loop to walk the string one character at a time, and since we're examining the end of the string, it makes sense to walk it backwards.
I'm assuming from your code (though it would be nice if you clarified it in your question) that you have a set of characters that are allowed at the end of a sentence, and you would like to leave these characters alone, but remove any additional spaces.
The logic, then, would be to start from the end of the string, and if a character is a valid ending character leave it alone. Otherwise, if it's a space, remove it. And finally, if it's neither then we're done.
Below is a method that uses this logic, along with a StringBuilder variable that is used to store the result. Starting at the end of the string, we capture the last characters, adding them to the result if they're valid and skipping them if they're spaces, until we reach a "regular" character, at which point we keep the rest of the string:
static string TrimEndSpaces(string input)
{
// If the input is null, there's nothing to do - just return null
if (input == null) return input;
// Our array of valid ending punctuation
char[] validEndingPunctuation = { '.', ':', ',', ';', '!', '?' };
// This will contain our final result
var result = new StringBuilder();
// Walk backwards through the input string
for (int i = input.Length - 1; i >= 0; i--)
{
if (validEndingPunctuation.Contains(input[i]))
{
// Valid character, so add it and keep going backwards
result.Insert(0, input[i]);
continue;
}
if (input[i] == ' ')
{
// Space character at end - skip it
continue;
}
// Regular character found - we're done. Add the rest of the string
result.Insert(0, input.Substring(0, i + 1));
break;
}
return result.ToString();
}
And here is an example usage, with some test sentences with varying endings of spaces, valid characters, null strings, empty strings, etc:
private static void Main()
{
var testInput = new List<string>
{
null,
"",
" ",
"Normal sentence test.",
"Test with spaces .",
"Test with multiple ending chars !?!?!",
"Test with only spaces at end ",
"Test with spaces after punctuation. ",
"Test with mixed punctuation and spaces ! ? ! ? ! "
};
foreach (var test in testInput)
{
// Format output so we can "see" null and empty strings
var original = test ?? "<null>";
if (original.Length == 0) original = "<empty>";
// Show original and the result. Wrap result in <> so we know where it ends.
Console.WriteLine($"{original.PadRight(50, '-')} = <{TrimEndSpaces(test)}>");
}
GetKeyFromUser("\nDone! Press any key to exit...");
}
Output
If you just want to remove them from the end, you can use:
if(myString.EndsWith(" ") == true)
{
myString = myString.TrimEnd();
}
Of course, you will need to consider the ending symbol ".", "!" or "?", you might want to exclude that char if the spaces are just before it.
Another approach would be:
var keepTrimming = true;
while(keepTrimming == true)
{
if(myString.EndsWith(" ") == true)
{
myString= myString.Remove(myString.Length - 1);
}
else
{
keepTrimming = false
}
}
I'm trying to remove single vowels from a string, but not if a vowel is double same.
For example string
"I am keeping a foobar"
should print out as
"m keepng foobr"
I have tried everything but didn't come up with a solution so far.
Try:
Regex.Replace(input, #"([aeiou])\1", "");
Though for I am keeping a foobar, it will give you m keepng foobr, which is different to your required m keepng foobr, as you're stripped spaces out of your required result, too.
If you want to remove the extraneous spaces, then it's a three step operation: remove vowels; remove proceeding/trailing spaces; remove double spaces.
var raw = Regex.Replace(input, #"([aeiou])\1", "");
var trimmed = raw.Trim();
var final = trimmed.Replace(" ", " ");
You could try this logic:
loop trough string and check two by two characters
if (isBothVowelsAndEqual()) do nothing; else removeFirstChar();
EDIT:
public List<char> vowels = "AEIOUaeiou".ToList();
public bool isBothVowelsAndEqual(char first, char second)
{
return (first == second && vowels.Contains(first));
}
const string s = "I am keeeping a foobar";
string output=String.Empty;
for (int i = 0; i < s.Length-1; i++)
{
if (isBothVowelsAndEqual(s[i], s[i + 1]))
{
output = output + s[i] + s[i+1];
i++;
}
else
{
if (!vowels.Contains(s[i])) {
output += s[i];
}
}
}
Console.WriteLine(output.Trim());
I want to replace all Special Characters which can't be parse in URL including space, double space or any big space with '-' using C#.
I don't want to use any Parse Method like System.Web.HttpUtility.UrlEncode.
How to do this ? I want to include any number of space between two words with just one '-'.
For example, if string is Hello# , how are you?
Then, Result should be, Hello-how-are-you, no '-' if last index is any special character or space.
string str = "Hello# , how are you?";
string newstr = "";
//Checks for last character is special charact
var regexItem = new Regex("[^a-zA-Z0-9_.]+");
//remove last character if its special
if (regexItem.IsMatch(str[str.Length - 1].ToString()))
{
newstr = str.Remove(str.Length - 1);
}
string replacestr = Regex.Replace(newstr, "[^a-zA-Z0-9_]+", "-");
INPUT:
Hello# , how are you?
OUTPUT:
Hello-how-are-you
EDIT:
Wrap it inside a class
public static class StringCheck
{
public static string Checker()
{
string str = "Hello# , how are you?";
string newstr = null;
var regexItem = new Regex("[^a-zA-Z0-9_.]+");
if (regexItem.IsMatch(str[str.Length - 1].ToString()))
{
newstr = str.Remove(str.Length - 1);
}
string replacestr = Regex.Replace(newstr, "[^a-zA-Z0-9_]+", "-");
return replacestr;
}
}
and call like this,
string Result = StringCheck.Checker();
string[] arr1 = new string[] { " ", "#", "&" };
newString = oldString;
foreach repl in arr1
{
newString= newString.Replace(repl, "-");
}
Of course you can add into an array all of your spec characters, and looping trough that, not only the " ".
More about the replace method at the following link
You need two steps to remove last special character and to replace all the remaining one or more special characters with _
public static void Main()
{
string str = "Hello# , how are you?";
string remove = Regex.Replace(str, #"[\W_]$", "");
string result = Regex.Replace(remove, #"[\W_]+", "-");
Console.WriteLine(result);
Console.ReadLine();
}
IDEONE
I have this string:
string myString = "do Output.printString(\"Do you want to Hit (h) or Stand (s)?\");";
My string as plain text:
do Output.printString("Do you want to Hit (h) or Stand (s)?");
I want to make it:
do Output . printString ("Do#you#want#to Hit#(h)#or#Stand#(s)?");
The idea is that there is a space between each word but if there is a string within apostrophes I want it to be WITHOUT SPACE and after this function I can do:
s.Split(' ');
and get the string in one string.
What I did is:
public static string PrepareForSplit(this string s)
{
string ret = "";
if (s.Contains("\""))
{
bool equalsAppear = false;
foreach (var nextChar in s)
{
char charToConcat;
if (nextChar == '"')
{
equalsAppear= equalsAppear == true ? false : true;
}
if (nextChar == ' ' && equalsAppear)
{
charToConcat = '#';
}
else
{
charToConcat = nextChar;
}
ret += charToConcat;
}
}
if (String.IsNullOrWhiteSpace(ret))
ret = s;
string[] symbols = {"{", "}", "(", ")", "[", "]", ".",
",", ";", "+", "-", "*", "/", "&", "|", "<", ">", "=", "~","#"};
foreach(var symbol in symbols)
if(ret.Contains(symbol))
{
if (!ret.Contains('"') || !((symbol=="-") || symbol==","))
{
ret = ret.Replace(symbol, " " + symbol + " ");
}
}
if(ret.Contains("\t"))
{
ret = Regex.Replace(ret, #"\t", " ");
}
return ret;
}
My problem is that in the end of this function I get this string:
do Output . printString ( "Do#you#want#to#Hit# ( h ) #or#Stand# ( s ) ?" ) ;
As you can see in the string that suppose to be without spacing I have spaces and then my program not behave as it should. Someone please help!
I would use a regular expression to extract your string.
You probably enter the starting string like this:
string source = "do Output.printString(\"Do you want to Hit (h) or Stand (s)?\");";
Try this regular expression:
\("([^\"]+)
The group between round brackets (i.e. the capturing group) is what you're looking for.
Edit: use it like this (based on http://www.dotnetperls.com/regex-match)
using System;
using System.Text.RegularExpressions;
class Program
{
static void Main()
{
// First we see the input string.
string source = "do Output.printString(\"Do you want to Hit (h) or Stand (s)?\");";
// Here we call Regex.Match.
Match match = Regex.Match(source, "\\(\"([^\"]+)");
// Here we check the Match instance.
if (match.Success)
{
// Finally, we get the Group value and display it.
string key = match.Groups[1].Value;
Console.WriteLine("result: "+ key);
}
else
{
Console.WriteLine("nothing found");
}
Console.ReadLine();
}
}
Edit2: now it works :-)
I suggest you to split the whole string at the apostrophes. This will make it much easier to differentiate between parts that are within apostrophes and the others.
string[] parts = s.Split('"');
Now you have:
part[0] ==> "do Output . printString ("
part[1] ==> "Do#you#want#to Hit#(h)#or#Stand#(s)?"
part[2] ==> ");"
I.e., the even indexes in part[] are outside the apostrophes, the odd indexes are within.
// Treat the parts not between apostrophes:
for (int i = 0; i < parts.Length; i += 2) {
part[i] = InsertSpacesBetweenWords(part[i]);
}
string result = String.Join("\"", part);
By the way: In your example, you can simplify
equalsAppear = equalsAppear == true ? false : true;
to
equalsAppear = !equalsAppear;
by using the logical NOT operator !.
Is there an easy method to insert spaces between the characters of a string? I'm using the below code which takes a string (for example ( UI$.EmployeeHours * UI.DailySalary ) / ( Month ) ) . As this information is getting from an excel sheet, i need to insert [] for each columnname. The issue occurs if user avoids giving spaces after each paranthesis as well as an operator. AnyOne to help?
text = e.Expression.Split(Splitter);
string expressionString = null;
for (int temp = 0; temp < text.Length; temp++)
{
string str = null;
str = text[temp];
if (str.Length != 1 && str != "")
{
expressionString = expressionString + "[" + text[temp].TrimEnd() + "]";
}
else
expressionString = expressionString + str;
}
User might be inputing something like (UI$.SlNo-UI+UI$.Task)-(UI$.Responsible_Person*UI$.StartDate) while my desired output is ( [UI$.SlNo-UI] + [UI$.Task] ) - ([UI$.Responsible_Person] * [UI$.StartDate] )
Here is a short way to insert spaces after every single character in a string (which I know isn't exactly what you were asking for):
var withSpaces = withoutSpaces.Aggregate(string.Empty, (c, i) => c + i + ' ');
This generates a string the same as the first, except with a space after each character (including the last character).
You can do that with regular expressions:
using System.Text.RegularExpressions;
class Program {
static void Main() {
string expression = "(UI$.SlNo-UI+UI$.Task)-(UI$.Responsible_Person*UI$.StartDate) ";
string replaced = Regex.Replace(expression, #"([\w\$\.]+)", " [ $1 ] ");
}
}
If you are not familiar with regular expressions this might look rather cryptic, but they are a powerful tool, and worth learning. In case, you may check how regular expressions work, and use a tool like Expresso to test your regular expressions.
Hope this helps...
Here is an algorithm that does not use regular expressions.
//Applies dobule spacing between characters
public static string DoubleSpace(string s)
{
if (string.IsNullOrEmpty(s))
{
return string.Empty;
}
char[] a = s.ToCharArray();
char[] b = new char[ (a.Length * 2) - 1];
int bIndex = 0;
for(int i = 0; i < a.Length; i++)
{
b[bIndex++] = a[i];
//Insert a white space after the char
if(i < (a.Length - 1))
{
b[bIndex++] = ' ';
}
}
return new string(b);
}
Well, you can do this by using Regular expressions, search for specific paterns and add brackets where needed. You could also simply Replace every Paranthesis with the same Paranthesis but with spaces on each end.
I would also advice you to use StringBuilder aswell instead of appending to an existing string (this creates a new string for each manipulation, StringBuilder has a smaller memory footprint when doing this kind of manipulation)