How to use Regex.Matches with a start index AND RegexOptions

Question

There doesn't seem to be a way to specify both RegexOptions and a start index when using Regex.Matches.

According to the docs , there is a way to do both individually, but not together.

In the example below, I want matches to contain only the second hEllo in the string text

string pattern = @"\bhello\b";
string text = "hello world. hEllo";
Regex r = new Regex(pattern);
MatchCollection matches;

// matches nothing
matches = r.Matches(text, 5)

// matches the first occurence
matches = Regex.Matches(text, pattern, RegexOptions.IgnoreCase)

Is there a different way to accomplish this?

Answer 1

I don't believe you can. You should instead instantiate Regex using the desired options:

Regex r = new Regex(pattern, RegexOptions.IgnoreCase);

and then you can simply use your existing code from the first sample, which should now match since we're using the IgnoreCase option:

matches = r.Matches(text, 5);

Applicable constructor docs

Try it online