How to concatenate strings -I know it's not that hard!

Question

2.50/5 (2 votes)

See more:

I have to process a wannabe XML string.
It hasn't got a root element (for reasons unknown), but I can't do much about it.

So I decided to stick a dummy root node around the entire XML and then feed it into the XMLDocument.

The XML in question looks like:

<mynode>
   blah
   <morenodes>
     blah
     blah
   </morenodes>
</mynode>
   blah
   <morenodes>
     blah
     blah
   </morenodes>

...

So to cheat, I decided to do

<root>
   <mynode>
     blah
     <morenodes>
       blah
       blah
     </morenodes>
   </mynode>
   <mynode>
     blah
     <morenodes>
       blah
       blah
     </morenodes>
   </mynode>
...
</root>

Thinking this is fairly straight forward, I did

string newString = "<root>" + oldString + "</root>";
XMLDocument xmlDolcument = new XMLDocument();
xmlDocument.Load(newString);

where oldString is where the original XML is found.

For some reason, the <Root> tag gets added OK, but the </Root> refuses to be added whatever I try.
What's so hard about string concatenation, and what am I doing that's so horribly wrong?

Please help!

[Edit] Formatting went wrong and the ending tag disappeared...

Posted 23-Feb-11 20:55pm

PaulowniaK

Updated 23-Feb-11 22:10pm

v2

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Accepted Answer · 2011-02-23T20:59:00

Solution 2

Your code (even if I view the raw source of your question) doesn't add the ending tag!
Try:

C#

string newString = "<root>" + oldString + "</root>";
XMLDocument xmlDolcument = new XMLDocument();
xmlDocument.Load(newString);

Posted 23-Feb-11 20:59pm

OriginalGriff

Comments

Wayne Gaylard 24-Feb-11 3:25am

Now the OP needs to combine both of these answers to come up with the correct solution - +5

Dalek Dave 24-Feb-11 3:42am

Good Call.

PaulowniaK 24-Feb-11 4:11am

The original question turned up a bit wrong, but the actual attempt looks pretty much like this suggestion.

Sergey Alexandrovich Kryukov · Accepted Answer · 2011-02-23T20:59:00

Solution 1

Be careful, remember, strings are immutable, so if you have several "+" operations, whole string is copied again and again every time.

Prefer System.Text.StringBuilder.Append. If you want to concatenate statically fixed number of strings (not a loop), prefer string.Format.

—SA

Posted 23-Feb-11 20:59pm

Sergey Alexandrovich Kryukov

Comments

CodingLover 24-Feb-11 3:03am

this is a good point to consider actually. immutable stuff is a real mess. try to avoid "+" as much as possible

Sergey Alexandrovich Kryukov 24-Feb-11 3:31am

Well, this is not mess, important feature -- functional approach.
--SA

Abhinav S 24-Feb-11 3:10am

1) good point
2) no idea why your answer was downvoted.
3) 5 to fix this univote.

Sergey Alexandrovich Kryukov 24-Feb-11 3:12am

Thank you.
Well, down-voters... savages...
--SA

Abhinav S 24-Feb-11 5:10am

:)

Pravin Patil, Mumbai 24-Feb-11 3:12am

My 5 too..
Good point....

Sergey Alexandrovich Kryukov 24-Feb-11 3:28am

Thank you.
--SA

Wayne Gaylard 24-Feb-11 3:24am

Good Advice - nice one.

Dalek Dave 24-Feb-11 3:43am

Excellent Answer.

PaulowniaK 24-Feb-11 4:12am

Thanks.
I tried it, but still no luck. :(
Only the starting tag gets added.

Sergey Alexandrovich Kryukov 24-Feb-11 12:08pm

This is not a matter of luck. You did it wrong. Do it carefully, that's it.
Or, perhaps more likely, you added correctly but did not realize it. Do you know, for example, that start and end tags are of the same element; you your example, only one DOM node? :-)
--SA

PaulowniaK 24-Feb-11 17:36pm

Of course the mention of "luck" is just a figure of speech... Anyway, the point is that it only has 1 DOM node, so yes, I am doing what I mean to do. I know this because if I write the entire string as I want it to appear directly in the code the XML Load() function works. It just fails if I build up the intended XML string within the code.

Sergey Alexandrovich Kryukov 24-Feb-11 18:36pm

Oh (sigh), then you need to show your code. Concatenating strings is way too easy to do it wrong for such a long time...
--SA

PaulowniaK 24-Feb-11 18:48pm

Here is my original attempt:

string strData = DataTerms.S_ROOT + m_strData + DataTerms.S_ROOT_END;
XmlDocument dataDoc = new XmlDocument();
dataDoc.LoadXml(strData);

Sergey Alexandrovich Kryukov 24-Feb-11 19:24pm

Did you use debugger? How could you have lost a tag? No way. Check is all three members of some are what you expect, then the result.
Wow!
--SA

PaulowniaK 24-Feb-11 19:33pm

Of course I used a debugger! ;)
I wrote out the DataTerms.S_ROOT_END to a separate string to check the content. That works fine. It just refuses to be added to the end of m_strData. I can check strData in the text viewer of the debugger but it won't show in the XML viewer (obviously).

Sergey Alexandrovich Kryukov 25-Feb-11 0:36am

Ah, this is nonsense. Refuses... be careful, that's all.
--SA