Doniyor Niyozov Doniyor Niyozov - 3 months ago 12
C# Question

How to replace some part of the text using regex c#

for example:

string str = $@"<html> < head > </ head > < body > <start> < h1 > Header 1 </ h1 > < p > A worker can be of 3 different types.</ p > <end> < p ></ p > </ body > </ html > "
string replacement = "hello world";
string newString = $@"<html> < head > </ head > < body > <start> < h1 > Header 1 </ h1 > < p > hello world</ p > <end> < p ></ p > </ body > </ html > "


So I have a
<start>
and
<end>
sign to know which part of the text should be replaced. How I can get the
newString
by regex.

Answer

Using Regex.Replace you set the pattern from the first <r> to the second, including all that is in between. Then you specify what to replace with.

var result = Regex.Replace(str, "<start>.*?<end>", $"<start> {replacement} <end>");

If prior to C# 6.0 string interpolation then:

var result = Regex.Replace(str, "<start>.*?<end>", string.Format("<start> {0} <end>",replacement));

With latest string from comments:

string str = $@"<html> < head > </ head > < body > <start> < h1 > Header 1 </ h1 > < p > A worker can be of 3 different types.</ p > <end> < p ></ p > </ body > </ html > ";
string replacement = "hello world";

var result = Regex.Replace(str, "<start>.*?<end>", $"<start> {replacement} <end>");