How can I get all HTML tags that contains certain text using regular expressions?

Question

I'm new to regex and I'm not able to do what I need.

Let's suppose we have this text:

<h1>Título</h1>
<h2>Los gatos felices</h2>
Existen una serie de gatos...
<h2 style="color:red" class="grande">los gatos: curiosidades</h2>
<p style='text-align: justify;' align='justify'>De por si 
<strong>los gatos</strong> saben saltar y además 
<strong>los perros odian a los gatos</strong>
</p>

And I need to get all tags that contains the "los gatos" text.

It should match 4 coincidences:

- <h2>Los gatos felices</h2>

- <h2 style="color:red" class="grande">los gatos: curiosidades</h2>

- <strong>los gatos</strong>

- <strong>los perros odian a los gatos</strong>

How can I solve it with a regular expression?

Edit:

I finally found what I need! I share it for anyone who might need it:

<(.*)([^<]*)>([^<]*)los gatos([^<]*)<\/\1>

Answer 1

Instead of Regex use a real Html parser like HtmlAgilityPack

var doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(yourhtmlstring);

var h2s = doc.DocumentNode.SelectNodes("//h2").Select(x => x.InnerText).ToList();