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Regex replace / search uses values ​​/ variables in search text

What is the regular expression syntax for using a matched expression part in a subsequent search part?

So, for example, if I have:
"{marker = 1} some text {/ marker = 1}"
or
"{marker = 2} some text {/ marker = 2}"

I want to use the first digit found in the pattern to find the second digit. So in "{marker = 1} {marker = 2} some text {/ marker = 2} {/ marker = 1}" the
regex will match 1 and then 2.

So far I have come up with {marker = (\ d)} (. *?) {/ Marker = (\ d)}, but I don't know how to specify the second \ d to refer to the value found in the first \ d.

I am doing this in C #.

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2 answers


try:   {marker=(\d)}(.*?){/marker=(\1)}



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A numbered backlink is just \ n, so \ 1 should work here:



Regex re = new Regex(@"\{marker=(\d)\}(.*?)\{/marker=(\1)\}");
// expect to work
Console.WriteLine(re.IsMatch(@"{marker=1}some text{/marker=1}"));
// expect to fail (end marker is different)
Console.WriteLine(re.IsMatch(@"{marker=1}some text{/marker=2}"));
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