Replace multiple characters in a C# string

Is there a better way to replace strings?

I am surprised that Replace does not take in a character array or string array. I guess that I could write my own extension but I was curious if there is a better built in way to do the following? Notice the last Replace is a string not a character.

myString.Replace(';', '\n').Replace(',', '\n').Replace('\r', '\n').Replace('\t', '\n').Replace(' ', '\n').Replace("\n\n", "\n");

You can use a replace regular expression.

s/[;,\t\r ]|[\n]{2}/\n/g

- `s/` at the beginning means a search
- The characters between `[` and `]` are the characters to search for (in any order)
- The second `/` delimits the search-for text and the replace text

In English, this reads:

"Search for `;` or `,` or `\t` or `\r` or ` ` (space) or exactly two sequential `\n` and replace it with `\n`"

In C#, you could do the following: (after importing `System.Text.RegularExpressions`)

Regex pattern = new Regex("[;,\t\r ]|[\n]{2}");
pattern.Replace(myString, "\n");

If you are feeling particularly clever and don't want to use Regex:

char[] separators = new char[]{' ',';',',','\r','\t','\n'};

string s = "this;is,\ra\t\n\n\ntest";
string[] temp = s.Split(separators, StringSplitOptions.RemoveEmptyEntries);
s = String.Join("\n", temp);

You could wrap this in an extension method with little effort as well.

Edit: Or just wait 2 minutes and I'll end up writing it anyway :)

public static class ExtensionMethods
{
public static string Replace(this string s, char[] separators, string newVal)
{
string[] temp;

temp = s.Split(separators, StringSplitOptions.RemoveEmptyEntries);
return String.Join( newVal, temp );
}
}

And voila...

char[] separators = new char[]{' ',';',',','\r','\t','\n'};
string s = "this;is,\ra\t\n\n\ntest";

s = s.Replace(separators, "\n");

This is the shortest way:

myString = Regex.Replace(myString, @"[;,\t\r ]|[\n]{2}", "\n");

Ohhh, the performance horror!
The answer is a bit outdated, but still...

public static class StringUtils
{
#region Private members

[ThreadStatic]
private static StringBuilder m_ReplaceSB;

private static StringBuilder GetReplaceSB(int capacity)
{
var result = m_ReplaceSB;

if (null == result)
{
result = new StringBuilder(capacity);
m_ReplaceSB = result;
}
else
{
result.Clear();
result.EnsureCapacity(capacity);
}

return result;
}


public static string ReplaceAny(this string s, char replaceWith, params char[] chars)
{
if (null == chars)
return s;

if (null == s)
return null;

StringBuilder sb = null;

for (int i = 0, count = s.Length; i < count; i++)
{
var temp = s[i];
var replace = false;

for (int j = 0, cc = chars.Length; j < cc; j++)
if (temp == chars[j])
{
if (null == sb)
{
sb = GetReplaceSB(count);
if (i > 0)
sb.Append(s, 0, i);
}

replace = true;
break;
}

if (replace)
sb.Append(replaceWith);
else
if (null != sb)
sb.Append(temp);
}

return null == sb ? s : sb.ToString();
}
}

Performance-Wise this probably might not be the best solution but it works.

var str = "filename:with&bad$separators.txt";
char[] charArray = new char[] { '#', '%', '&', '{', '}', '\\', '<', '>', '*', '?', '/', ' ', '$', '!', '\'', '"', ':', '@' };
foreach (var singleChar in charArray)
{
str = str.Replace(singleChar, '_');
}