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Handling nulls in tab-delimited string?

Apparently, the Split method handles consecutive tabs as a single delimiter. Does anyone have any suggestions for handling consecutive tabs?

I am reading in text files that contain lines of tab-delimited data. I was using string[] stringArray = lineOfText.Spli t('\t') to automatically populate an array used to populate the values in a new DataRow.

However, sometimes the lines of text contain null values. I can find these null values by opening the file in a text editor and using the arrow keys locate consecutive Tabs with, presumably, a null value between them.

Any help is greatly appreciated.

- VS
Nov 16 '05 #1
4 6857
Vagabond Software <carlfenley-X-@-X-san.rr.com> wrote:
Apparently, the Split method handles consecutive tabs as a single
delimiter.


String.Split doesn't. For instance:

using System;

public class Test
{
static void Main()
{
string x ="a\t\tb";
string[] values = x.Split();
foreach (string value in values)
{
Console.WriteLi ne(value);
}
}
}

prints "a" then a blank line (the empty value) then "b".

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Nov 16 '05 #2
"Jon Skeet [C# MVP]" <sk***@pobox.co m> wrote in message news:MP******** *************** *@msnews.micros oft.com...
Vagabond Software <carlfenley-X-@-X-san.rr.com> wrote:
Apparently, the Split method handles consecutive tabs as a single
delimiter.


String.Split doesn't. For instance:

using System;

public class Test
{
static void Main()
{
string x ="a\t\tb";
string[] values = x.Split();
foreach (string value in values)
{
Console.WriteLi ne(value);
}
}
}

prints "a" then a blank line (the empty value) then "b".


Thanks for the reply. I discovered late last night that it was I who was mishandling the consecutive tabs and not the Split method.

- VS
Nov 16 '05 #3
As you've already discovered, Split() does work correctly for the situation
you mentioned; however one thing it doesn't work correctly for is
quote-delimited strings containing the field delimiter itself. For example,
in a comma-delimited file:

Joe,Schumuck,"1 23 Maple St, Apt 4",Anytown,CA,9 0000

Would be mis-parsed as Split() is not designed to recognize a delimiter
within a quoted string as not being a delimiter.

You would have to write your own routine to handle situations like that.

I mention this in case quoted strings are possible in your input.

--Bob

"Vagabond Software" <carlfenley-X-@-X-san.rr.com> wrote in message
news:%2******** *******@TK2MSFT NGP11.phx.gbl.. .
Apparently, the Split method handles consecutive tabs as a single delimiter.
Does anyone have any suggestions for handling consecutive tabs?

I am reading in text files that contain lines of tab-delimited data. I was
using string[] stringArray = lineOfText.Spli t('\t') to automatically
populate an array used to populate the values in a new DataRow.

However, sometimes the lines of text contain null values. I can find these
null values by opening the file in a text editor and using the arrow keys
locate consecutive Tabs with, presumably, a null value between them.

Any help is greatly appreciated.

- VS
Nov 16 '05 #4
"Bob Grommes" <bo*@bobgrommes .com> wrote in message news:Od******** ******@TK2MSFTN GP10.phx.gbl...
As you've already discovered, Split() does work correctly for the situation
you mentioned; however one thing it doesn't work correctly for is
quote-delimited strings containing the field delimiter itself. For example,
in a comma-delimited file:

Joe,Schumuck,"1 23 Maple St, Apt 4",Anytown,CA,9 0000

Would be mis-parsed as Split() is not designed to recognize a delimiter
within a quoted string as not being a delimiter.

You would have to write your own routine to handle situations like that.

I mention this in case quoted strings are possible in your input.


I certainly appreciate the tip. Though I have not run into quoted data yet, there are literally thousands of the client's files I have not yet run through my parser. There's no telling what I might find.

- VS
Nov 16 '05 #5

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