I have a string where the third last character is sometimes a , If this is the case I want to replace it with a . The string could also have other ,'s throughout. Is there an elegant solution to this?
EDIT: Thanks everyone for your answers. Just to clarify, yes by third last I mean a string of the form xxxxxx,xx (it's a european currency thing)
How about:
if (text[text.Length - 3] == ',')
{
StringBuilder builder = new StringBuilder(text);
builder[text.Length - 3] = '.';
text = builder.ToString();
}
EDIT: I hope the above is just about the most efficient approach. You could try using a char array instead:
if (text[text.Length - 3] == ',')
{
char[] chars = text.ToCharArray();
chars[text.Length - 3] = '.';
text = new string(chars);
}
Using Substring will work as well, but I don't think it's any more readable:
if (text[text.Length - 3] == ',')
{
text = text.Substring(0, text.Length - 3) + "."
+ text.Substring(text.Length - 2);
}
EDIT: I've been assuming that in this situation you already know that text will be at least three characters length. If that's not the case, you'd obviously want a test for that as well.
string text = "Hello, World,__";
if (text.Length >= 3 && text[text.Length - 3] == ',')
{
text = text.Substring(0, text.Length - 3) + "." + text.Substring(text.Length - 2);
}
// text == "Hello, World.__"
A more proper method would probably be to use the cultures
string input = "12345,67";
System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("nl-NL");
decimal value = System.Convert.ToDecimal(input);
System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
string converted = string.Format("{0:C}", value);
Try this
System.Text.RegularExpressions.Regex.Replace([the_string], "(,)(.{2})$", ".$2")
It should do it if by 'third last character' you literally mean the third-last character in the whole string.
That said - you might need to tweak if there are new lines - e.g. add the RegexOptions.Singleline enum as an extra parameter.
For better performance - probably - you could pre-declare the regex inside a class body:
static readonly Regex _rxReplace = new Regex("(,)(.{2})$", RegexOptions.Compiled);
Then when you want to use it it's just:
var fixed = _rxReplace.Replace([the_string], ".$2");
string.Format("{0:0.00}", 275.95, System.Globalization.CultureInfo.CreateSpecificCulture("nl-BE"));with the correct culture? This example would return 275,95