Linq, Array and replace text in multiple line

Question

5.00/5 (1 vote)

See more:

Hi Friends,

a new question in text changing with linq.

I have a long string that can be splitted ino an array of lines
I want to update only somelines in the array with a specific text and after update join all the lines to 1 string again.

I know how to update line by line and call the method recursive untill no more occurrences are found. But something tells me I could adjust all these lines in 1 linq call.

now written:

C#

if (completeText.Contains("exception for sqlstate value"))
            {
                string[] stringSeparators = new string[] { "\n" };
                string[] lines = completeText.Split(stringSeparators, StringSplitOptions.None);

                var line = lines.Where(x=>x.Contains("exception for sqlstate value") && !x.Trim().StartsWith("--"));
                if (line.Count() > 0)
                {
                    string lineNew = "--" + line.First().Trim();
                    completeText = completeText.Replace(line.First().Trim(), lineNew);
                    if (line.Count() > 1)
                        completeText = CheckForSqlStateValue(completeText);
                }
            }
            return completeText;

How to change in 1 call without recursive methods calls?

Posted 1-Oct-15 0:20am

Herman<T>.Instance

Add a Solution

Comments

Nathan Minier 1-Oct-15 7:38am

The only issue I'm seeing is the multiple enumerations. You could just assign var first = lines.First() and work from there.

Have you tried something like:

var line = lines.Where(x=>x.Contains("exception for sqlstate value") && !x.Trim().StartsWith("--")).First().Select(x => { x = "--" + x.Trim() })

Herman<T>.Instance 1-Oct-15 7:56am

I understand your idea, but I want:
lines = lines.Where(x => x....) with a replace funcionality.

Nathan Minier 1-Oct-15 8:09am

There's a tiny extension method on SO that would work:
http://stackoverflow.com/questions/200574/linq-equivalent-of-foreach-for-ienumerablet

Nice debate about it as well.

Herman<T>.Instance 1-Oct-15 8:38am

Tried ForEacth without succes

Maciej Los 1-Oct-15 8:26am

var lines = completeText.Split(stringSeparators, StringSplitOptions.None).Where(x=>x.Contains("exception for sqlstate value") && !x.Trim().StartsWith("--"));

???

Herman<T>.Instance 1-Oct-15 8:53am

That only gives a collection with the lines with that value. But I also want to replace that textpart. My complete Lines[] array stays intact. That is what I try

Herman<T>.Instance 1-Oct-15 9:11am

Array.ForEach(lines, item => item = item.Replace("exception for sqlstate value", "int ="));

and even than the lines with the exception text do not get changed

Maciej Los 1-Oct-15 9:24am

OK. Do you want to return completetext after changes or do you want to return only those lines which meet criteria?

Herman<T>.Instance 1-Oct-15 9:30am

the completeText

1 solution

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)

Maciej Los · Accepted Answer · 2015-10-01T03:35:00

If i understand you well... you want to replace "exception for sqlstate value" with "int =" if a line does not start with "--".

If you want to return all lines with changed values, try this:

C#

string[] lines = completeText.Split(stringSeparators, StringSplitOptions.None)
		.Select(item=>item.Contains("a") && !item.Trim().StartsWith("--") ? item.Replace("a", "int=") : item)
		.ToArray();

Complete - tested - example:

C#

string completeText = "a\nb\nc\n--a\ne\nf\na\nh\ni\n--a\nk\nl";
string[] stringSeparators = new string[] { "\n" };
string[] lines = completeText.Split(stringSeparators, StringSplitOptions.None)
        .Select(item=>item.Contains("a") && !item.Trim().StartsWith("--") ? item.Replace("a", "int=") : item)
        .ToArray();

Returns an array:

int=
b
c
--a
e
f
int=
h
i
--a
k
l

But...
If you want to return lines which meet your criteria, use Where + Select