Trim not working on null characters

Question

I have a really bizarre problem with trim method. I'm trying to trim a string received from database. Here's my current method:

string debug = row["PLC_ADDR1_RESULT"].ToString();
SPCFileLog.WriteToLog(String.Format("Debug: ${0}${1}",debug,Environment.NewLine));
debug = debug.Trim();
SPCFileLog.WriteToLog(String.Format("Debug2: ${0}${1}", debug, Environment.NewLine));
debug = debug.Replace(" ", "");
SPCFileLog.WriteToLog(String.Format("Debug3: ${0}${1}", debug, Environment.NewLine));

Which produces file output as following:

Debug: $    $
Debug2: $    $
Debug3: $    $ 

Examining the hex codes in file revealed something interesting. The supposedly empty spaces aren't hex 20 (whitespace), but they are set as 00 (null?)

How our database contains such data is another mystery, but regardless, I need to trim those invalid (?) null characters. How can I do this?

Answer 1

If you just want to remove all null characters from a string, try this:

debug = debug.Replace("\0", string.Empty);

If you only want to remove them from the ends of the string:

debug = debug.Trim('\0');

There's nothing special about null characters, but they aren't considered white space.

Answer 2

String.Trim() just doesn't consider the NUL character (\0) to be whitespace. Ultimately, it calls this function to determine whitespace, which doesn't treat it as such.

Frankly, I think that makes sense. Typically \0 is not whitespace.