Question

I am having a problem finding the correct match for all the cases.
I want to catch something string( here in my example ##xyx##) which is in the quotes for example,
if i have something like

Case 1)

               <picture href="hello" ##xyz##>##xyz##</picture>

the output should be no match found as none of them are in quotes.

if i have a different case something like

case 2)

            <picture href="##xyz##" dbhdfbhg="dbfdhfbhgbt fgkg ##xyz## hdjvffhgfhd">

i want to match both the cases which have ##xyz## as both of them are in quotes

case 3)

              <picture href="##xyz##">
                    ##xyz##
                     </picture>

the regular expression should only catch the teh first one but not the second one ..

i have tried something like (“)([^”].)?(##xyz##)([^”].)?(“)
which gets the wrong output.
in the case 3 its catching the second one even though i use multiline option in regex. can some one help?
I am using C# for coding

Answer 1

You could try something like the following LINQPad snippet. The regular expression uses a lookahead (?= to find a matching quote and then tries to match ##xyz## within that text segment:

var text = "<picture href=\"##xyz##\" dbhdfbhg=\"dbfdhfbhgbt fgkg ##xyz## hdjvffhgfhd\">";
var text1 = @"<picture href=""##xyz##"">
                    ##xyz##
                    </picture>";

var regex = new Regex("\"(?=[^\"]+)[^#]*##xyz##[^\"]*\"");

var matches = regex.Matches(text);
var matches1 = regex.Matches(text1);
matches.Dump();
matches1.Dump();

This gives the following correct output (i.e. two matches in first string and only one match in second):