http://undefinedbehavior.co.uk/Recent content on undefined behaviorHugoen-gbSun, 14 Jun 2026 00:00:00 +0000http://undefinedbehavior.co.uk/posts/1-5-comments/Sun, 14 Jun 2026 00:00:00 +0000http://undefinedbehavior.co.uk/posts/1-5-comments/Single-line vs multi-line comments, why over-commenting is its own bug, and commenting out code for debugging.http://undefinedbehavior.co.uk/posts/1-1-statements-and-the-structure-of-a-program/Mon, 01 Jun 2026 00:00:00 +0000http://undefinedbehavior.co.uk/posts/1-1-statements-and-the-structure-of-a-program/Starting from zero — what a statement is, what a function is, and why every C++ program needs exactly one main().http://undefinedbehavior.co.uk/about/Mon, 01 Jan 0001 00:00:00 +0000http://undefinedbehavior.co.uk/about/<p>I&rsquo;m Dan — a QA engineer at Jagex by day, currently teaching myself C++ by working through <a href="https://www.learncpp.com">learncpp.com</a> and <a href="https://www.youtube.com/@TheCherno">The Cherno&rsquo;s</a> C++ series on YouTube.</p> <p>This is the log of that process: what I read, what I watched, what clicked, and what didn&rsquo;t. Lessons are numbered where they map onto learncpp.com so you can follow along or skip straight to the topic you care about.</p> <p>Undefined behavior, for the uninitiated, is what happens when C++ code does something the standard doesn&rsquo;t define the outcome of — the compiler is allowed to do <em>anything</em>, including working perfectly, right up until it doesn&rsquo;t. Felt like an honest name for a blog documenting the process of learning a language full of sharp edges.</p>