Test, validate and match regular expressions
This regex matches HTML anchor tags linking to StackExchange questions, using three named capture groups to separately extract the opening <a> tag with the question URL (/questions/ followed by a numeric ID), the link text (typically the question title), and the closing </a tag. The lazy quantifier after the digits ensures the href match stops at the first closing quote, while the greedy .+ captures the full anchor text. It's designed for web scrapers harvesting question links and titles from StackOverflow or other StackExchange sites.