https://ghafoorsblog.com/tags/higher-order-functions/Recent content in Higher-Order-Functions on Ghafoor's Personal BlogHugoenhello@ghafoorsblog.com (AG Sayyed)hello@ghafoorsblog.com (AG Sayyed)Copyright © 2024-2026 AG Sayyed. All Rights Reserved.Sun, 24 May 2026 09:13:13 +0100https://ghafoorsblog.com/posts/js/05b-functions-advanced/Thu, 26 Jun 2025 08:00:00 +0000hello@ghafoorsblog.com (AG Sayyed)https://ghafoorsblog.com/posts/js/05b-functions-advanced/<h2 id="beyond-the-basics">Beyond the basics</h2> <p>The <a href="https://ghafoorsblog.com/posts/js/05a-functions-basics/" >previous post</a> covered how functions are defined and called. This one tackles the parts that come up in every interview and every code review: <strong>closures</strong>, the <strong><code>this</code> binding</strong>, and the <strong>higher-order patterns</strong> that make JavaScript expressive.</p> <h2 id="closures">Closures</h2> <p>A <em>closure</em> is the combination of a function and the lexical environment it was created in. When a function is created, it captures references to every variable it can see at that moment. Those variables remain alive for as long as the function does — even after the outer scope has otherwise been garbage-collected.</p>