How do I replace multiple spaces with a single space in C#?

Question

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         


        

Answer 1

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 " ) );

Answer 2

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.

Answer 3

string sentence = "This is a sentence with multiple    spaces";
RegexOptions options = RegexOptions.None;
Regex regex = new Regex("[ ]{2,}", options);     
sentence = regex.Replace(sentence, " ");

Answer 4

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.

Answer 5

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, " ");

Answer 6

string xyz = "1   2   3   4   5";
xyz = string.Join( " ", xyz.Split( new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries ));