trim all strings in an array

Question

I have a string that comes in like:

string email = "[email protected], [email protected], [email protected]";

I want to split it into an array of strings

If I do this:

string[] emails = email.Split(',');

I get spaces in front of each email address (after the first one):

emails[0] = "[email protected]"
emails[1] = " [email protected]"
emails[2] = " [email protected]"

What is the best way to get this (either a better way to parse or a way to trim all strings in an array)?

emails[0] = "[email protected]"
emails[1] = "[email protected]"
emails[2] = "[email protected]"

If the space will always be there, you could add it to the split... ie: email.Split(', '); — nilamo
– nilamo, Commented Aug 31, 2009 at 4:02

Bryan Watts · Accepted Answer · 2009-08-31 04:19:42Z

265

emails.Split(',').Select(email => email.Trim()).ToArray()

answered Aug 31, 2009 at 4:19

Bryan Watts

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8 Comments

Bryan Watts Over a year ago

@Moismyname: I'm not sure what constraint would lead you down that path, but there are other answers that address your question.

klaas Over a year ago

First: very nice solution ! Regarding the question of the OP shouldn't it be email.Split(...)... instead of emails.Split(..)... ? I think emails is already the split array.

daveD Over a year ago

This is better than the accepted answer, as the question was to TRIM each string, not necessarily replace spaces with blanks.

Bryan Watts Over a year ago

@IrfanUllah: Chain a .Where(email => email != null)

Bryan Watts Over a year ago

@MinhTran It is indeed a function call - Select is a family of extension methods that make up LINQ in the System.Linq namespace.

|

Community · Accepted Answer · 2011-08-05 10:15:14Z

42

You could also replace all occurrences of spaces, and so avoid the foreach loop:

string email = "[email protected], [email protected], [email protected]";    
string[] emails = email.Replace(" ", "").Split(',');

edited Aug 5, 2011 at 10:15

CommunityBot

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answered Aug 31, 2009 at 4:00

nick2083

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5 Comments

revgum Over a year ago

Works ok for this specific example, but doesn't maintain spaces for the resultant elements like; "foo bar, another element, blah_blah". Bryan Watts has the best answer IMO.

nick2083 Over a year ago

Hi @revgum! That's true, but I have sticked to comply @leora's requirements. The example you´re describing, IMO, is outside the context of this question. Thanks anyway for your feedback.

Scott Adams Over a year ago

-1 I agree that this is not a good thing to do. Buyer beware.

Joris Van Regemortel Over a year ago

also downvoted. i agree that the answer does the trick, but Bryans answer is more useful in general

SimpleGuy Over a year ago

This isn't right. It will not trim, but remove spaces from strings in array, which is totally different from trim (removing trailing and leading spaces)

Sam Harwell · Accepted Answer · 2009-08-31 04:01:46Z

23

Either one of the following would work. I'd recommend the first since it more accurately expresses the joining string.

string[] emails = email.Split(new string[] { ", " }, StringSplitOptions.None);
string[] emails = email.Split(new char[] { ' ', ',' }, StringSplitOptions.RemoveEmptyEntries);

answered Aug 31, 2009 at 4:01

Sam Harwell

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3 Comments

Brian Rasmussen Over a year ago

+1 I didn't know about the options. Coming from Perl I see regexs everywhere. With the options Split is the way to go.

Stan R. Over a year ago

+1 we use LINQ so much that we tend to forget that other elegant options do exist.

Moses Over a year ago

In this specific case, email addresses can't have spaces, so I would use the second option.

skalb · Accepted Answer · 2009-08-31 04:02:24Z

11

You can use Trim():

string email = "[email protected], [email protected], [email protected]";
string[] emails = email.Split(',');
emails = (from e in emails
          select e.Trim()).ToArray();

edited Aug 31, 2009 at 4:02

answered Aug 31, 2009 at 3:53

skalb

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1 Comment

Andrew Hare Over a year ago

This answer is correct but is overkill, this answer has the best approach: stackoverflow.com/questions/1355704/…

Brian Rasmussen · Accepted Answer · 2009-08-31 04:01:15Z

8

Use Regex.Split to avoid trimming

var emails = Regex.Split(email, @",\s*");

answered Aug 31, 2009 at 4:01

Brian Rasmussen

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Comments

formicini · Accepted Answer · 2021-01-06 11:15:00Z

7

.NET 5 has arrived and with it, a modern solution to this problem:

string[] emails = email.Split(',', StringSplitOptions.TrimEntries);

answered Jan 6, 2021 at 11:15

formicini

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1 Comment

cdie Over a year ago

This should be considered as the best option, as it's more perf than any other answer here

mr.martan · Accepted Answer · 2011-02-10 14:18:40Z

5

You can use a one line solution like this:

string[] emails = text.Split(',', StringSplitOptions.RemoveEmptyEntries);
Array.ForEach<string>(emails, x => emails[Array.IndexOf<string>(emails, x)] = x.Trim());

answered Feb 10, 2011 at 14:18

mr.martan

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Comments

Teodor Tite · Accepted Answer · 2019-07-18 16:05:03Z

4

If you just need to manipulate the entries, without returning the array:

string[] emails = text.Split(',');
Array.ForEach(emails, e => e.Trim());

answered Jul 18, 2019 at 16:05

Teodor Tite

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Comments

Jan Zich · Accepted Answer · 2009-08-31 04:11:08Z

2

Alternatively, you can split using a regular expression of the form:

\s*,\s*

i.e.

string[] emails = Regex.Split(email, @"\s*,\s*");

It will consume the surrounding spaces directly.

Regular expressions are usually a performance hit, but the example you gave indicates that this is something you plan to do once in your code for a short array.

edited Aug 31, 2009 at 4:11

answered Aug 31, 2009 at 3:57

Jan Zich

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Comments

RonSanderson · Accepted Answer · 2016-03-17 20:33:01Z

1

The answer from Bryan Watts is elegant and simple. He implicitly refers to the array of strings created by the Split().

Also note its extensibility if you are reading a file, and want to massage the data while building an array.

string sFileA = @"C:\Documents and Settings\FileA.txt";
string sFileB = @"C:\Documents and Settings\FileB.txt";

// Trim extraneous spaces from the first file's data
string[] fileAData = (from line in File.ReadAllLines( sFileA )
                      select line.Trim()).ToArray();

// Strip a second unneeded column from the second file's data
string[] fileBData = (from line in File.ReadAllLines( sFileB )
                      select line.Substring( 0, 21 ).Trim()).ToArray();

Of course, you can use the Linq => notation if you prefer.

string[] fileBData = File.ReadAllLines( sFileB ).Select( line =>
                             line.Substring( 0, 21 ).Trim()).ToArray();

Although my answer should have been posted as a comment, I don't have enough reputation points to comment yet. But I found this discussion invaluable in figuring out how to massage data while using ReadAllLines().

answered Mar 17, 2016 at 20:33

RonSanderson

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2 Comments

RoadieRich Over a year ago

Wecome to Stack Overflow. One small point on your code: If you're using Linq like that, you might be better using File.ReadLines. ReadAllLines "slurps" the entire file into an array in memory, which can obviously be problematic with big files. ReadLines only reads one line at a time, which is great if you don't need to keep the initial version of the contents.

RonSanderson Over a year ago

Thanks! I can see that the example using ReadAllLines will break down for very large files, containing both the raw data and the trimmed versions in memory at the same time, for a moment. The documentation page for File.ReadLines() also has an example that fits in with this discussion.

jscharf · Accepted Answer · 2009-08-31 03:54:53Z

0

Use String.Trim in a foreach loop, or if you are using .NET 3.5+ a LINQ statement.

answered Aug 31, 2009 at 3:54

jscharf

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Comments

Dan · Accepted Answer · 2022-05-14 19:24:22Z

0

In .NET 5, they added StringSplitOptions.TrimEntries.

You can use it like

string[] emails = email.Split(',', StringSplitOptions.TrimEntries);

Which will give you

emails[0] = "[email protected]"
emails[1] = "[email protected]"
emails[2] = "[email protected]"

answered May 14, 2022 at 19:24

Dan

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