Replacing a string ignoring case, but keeping original case reference

Question

User-195907812 posted

Hi,

I am creating a search results page and I generate the output in the code behind as a string.

If the user searches for "fox", I'd like to replace the word fox with "<span class='highlight'>fox</div>".

So "THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG"

becomes "THE QUICK BROWN <span class='highlight'>fox</div> JUMPS OVER THE LAZY DOG".

This is easily done using:

output = Regex.Replace(output, query, "<span class='highlight'>" + query + "</span>" , RegexOptions.IgnoreCase);

However, I'd like to ensure I keep the case of the original string when I replace it - how would I do this?

Answer 1

User475983607 posted

I'm guessing you really want to add markup to a string not replace words.  If so, see the following.

https://forums.asp.net/t/1677808.aspx?Highlight+matched+text+in+a+string+using+c+

Answer 2

User2103319870 posted

, I'd like to ensure I keep the case of the original string when I replace it - how would I do this?

You could use Regex.Matches to find the exact match from sentence and then replace it like below

string query = "fox";

string output = "THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG";
Regex rgx = new Regex(query, RegexOptions.IgnoreCase);
MatchCollection matches = rgx.Matches(output);
if (matches.Count > 0)
{
output = Regex.Replace(output, query, "<span class='highlight'>" + matches[0] + "</span>", RegexOptions.IgnoreCase);
}

• Sample Demo

Answer 3

User-195907812 posted

Thank you both, great solutions - I went with A2H's version due to simplicity.