--- title: Idle JavaScript Observations author: George Mandis date: 2021-06-04 description: Further adventures in JavaScript tags: post, post, useless, javascript --- There are lots of blogs that post useful tips and observations about programming in JavaScript and other languages. This is not one of them. Sometimes I like to look at the `label` documentation for JavaScript on MDN and ponder unusual ways I can use it: ``` https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/label ``` The way [Svelte makes use of the label syntax](https://svelte.dev/docs#3_$_marks_a_statement_as_reactive) is actually kind of interesting. When I did a deep-dive into that framework last year this jumped out. But a deep-dive into labels and scoping might actually be useful. This post is just to let you know that this is valid JavaScript: ``` https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/label ``` In fact, copying-and-pasting just about any URL is probably valid JavaScript. Why is this? - The http(s) protcol gets interpreted as the aforementioned `label`. - The // immediately following the label starts a comment. The lowdown: you can copy and paste just about any website directly into your JavaScript code without modification and it won't break anything. Is this useful? Not really. Just a funny observation I learned the hard way, when I forgot to copy out the reference to some documentation elsewhere in my code. → **Filed under**: [Useless JavaScript](/useless-javascript).