.Contains or delimeters

Glenn Patton

Hi All,

I am loading in data putting it in a string variable and the going through it with a
char[] delimetersChars = { '\n', '\r'};
and a string[] Values = FileData.Split(delimetersChars);

The delimetersChars had the < & > chars as I am using those to denote the start & end of messages. In the act of spotting possible errors as the data is not always reliable...

if (!Values[a].Contains('<') || !Values[a].Contains('>'))
Values[a] = "";
My thinking was this would check to see if there is an < & > is there an easier (better) way to do this.

Glenn

21 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes14y ago
Accepted answer
I'm sure the regular expression works. This is how I tested it with various strings

string regExp = @"(?<=<).+?(?=>)";
string[] strings = { "ssss", "sss", "", "ss" };

foreach (string s in strings)
{
MatchCollection mc = Regex.Matches(s, regExp);
if (mc.Count > 0)
{
string temp = "";

foreach (Match m in mc)
{
temp += m.Value + "\n";
}

rtbFormattedData.Text += temp;
}
}

The output in the RTB should be:

abc
def
ghi
jkl
Glenn Patton14y ago
Thanks again!
Vulpes14y ago
Yeah, the dot (.) was vital - it means match any character other than \n.

Here's a couple of good articles on regular expressions:

http://www.codeproject.com/Articles/9099/The-30-Minute-Regex-Tutorial

http://www.c-sharpcorner.com/UploadFile/Kolonist/regularexpressions07042006083534AM/regularexpressions.aspx
Glenn Patton14y ago
Solved it! nights sleep & coffee revealed a lack . in the reg expression string regExp = @"(?<=<)+?(?=>)";
instead of string regExp = @"(?<=<).+?(?=>)";
Know of a good source for RegEx for the unknowing
Thanks Glenn
Glenn Patton14y ago
Morning, What I was after was an expression method to go through the below text and disregard the aaaa and have the rest:

<123456789987654321><987654321987654321><123456321321111><12345678998765432111111111111>aaaaa

I suppose I should have mention it earlier!

Glenn
Vulpes14y ago
The regular expression is designed to pick out any characters between '<' and '>' excluding those delimiters themselves. Any other characters are ignored.

Is that not what's wanted?
Glenn Patton14y ago
The actual data as a string eg aaaa XXX & YYYY are numbers don't know how big as yet but valid reading seperated by < > aaaa is invalid.
Vulpes14y ago
What's in the rtbData box?
Glenn Patton14y ago
I wasn't doubting you rest assured! It's just that I have never used RegEx. I need to fiddle more!
The code I have is below but from the debugger I am not going in the the if,
any ideas?
string regExp = @"(?<=<)+?(?=>)";
//char[] delimetersChars = { '\n', '\r' };
//char[] delimeterCharFurther = { '<', '>' };
//int Location = 0;
string FileData;

FileData = rtbData.Text;
MatchCollection mc = Regex.Matches(FileData, regExp);
if (mc.Count > 0)
{
string temp = "";
foreach (Match m in mc)
{
temp += m.Value + "\n";
}
rtbFormattedData.Text += temp;
}
Glenn Patton14y ago
Have copied it over stepping through it seems as if the 'if'(if(mc.Count)) is always = 0 so it never enters. if there is an equals and it enters the loop nothing happens, (regular expressions are a bit of a new area for me). (must remember . not ; when typing messages!)
Glenn Patton14y ago
Have copied it over stepping through it seems as if the 'if'(if(mc.Count)) is always = 0 so it never enters. if there is an equals and it enters the loop nothing happens, (regular expressions are a bit of a new area for me). (must remember . not ; when typing messages!)
Vulpes14y ago
I'd try using regular expressions:

using System.Text.RegularExpressions;

// ....

string regExp = @"(?<=<).+?(?=>)";
MatchCollection mc = Regex.Matches(FileData, regExp);
if (mc.Count > 0)
{
string temp = "";

foreach(Match m in mc)
{
temp += m.Value + "\n";
}

rtbFormattedData.Text += temp;
}
Glenn Patton14y ago
I think the previous method was getting too involved (I really want a method of finding which bits of data enclosed in < & > and throwing any that aren't)
I am trying now
the delimeterCharFurther is a character array of < >, the below code appears to take out the < & > and blanks but includes data the does not have the enclosing < >

Glenn
string[] Values = FileData.Split(delimeterCharFurther);

for (int a = 0; a <= Values.Length - 1; a++)
{
if(String.Empty!=Values[a])
rtbFormattedData.Text += Values[a]+"\n";
}
Vulpes14y ago
You can cause an 'if' statement to be repeated until you get the 'right' result by wrapping it in a 'while' statement:

for(;;)
{
// do some processing

while(true)
{
if(condition)
{
// do some processing
if(result) break; // breaks from 'while' but not 'for'
}
}
}
Glenn Patton14y ago
The idea I had works only if two bits of data are not separated properly if there is more than one reading on the same line it ignores. If a break is used that will cause the for loop to be broken not the if, I need a sort of EndIf does that make sense?
I need it to restart the if()
Glenn Patton14y ago
Thanks!
Vulpes14y ago
As long as the string variable can't be null, you have solved it - I'm only suggesting a simplification :)
Glenn Patton14y ago
Nuts, just when you think I solved that one!
Glenn Patton14y ago
Nuts, just when you think I solved that one!
Vulpes14y ago
The StartsWith and EndsWith methods still work correctly even if a string is empty, so you could simplify that to:

if (Values[a].StartsWith("<") && Values[a].EndsWith(">"))
MessageBox.Show(Values[a].Replace("<", "").Replace(">", ""));

However, if there was any possibility that values[a] could be null (not the same as empty), you'd need to put a check in for that.
Glenn Patton14y ago
Hi,

May have solved this my self what is the learned view of the below:
if ((String.Empty != Values[a]) && ((Values[a].StartsWith("<") && Values[a].EndsWith(">"))))
MessageBox.Show(Values[a].Replace("<", "").Replace(">", ""));
seems to work? but is it to standard?

Glenn