In my post about GIFs, I pointed out that the creators of the GIF file format explicitly said that it wasn’t meant to be a great format for animations, but since it was widely available in people’s browsers, and no-one actually read that spec, it ended up being used for animations all over the place anyway, and now it’s all the format is known for. By opening a technological window, and allowing some limited animations to be stored in .gif files, they closed a door (new file formats with more advanced compression are constantly pushed back on because people are used to GIFs.)

Unrelatedly, here are two keywords that exist in JavaScript: const and let. let creates a variable that can have a new value assigned to it later, while const creates a variable that will always have the same value attached to it. const is the typical way that people declare variables in modern JavaScript; thanks largely to linting rules and style guides like the Airbnb JavaScript style guide, which for whatever reason was very popular back in the day, a generation of programmers learned that changing the values of variables was to be avoided, and obviously const is the way to do that, right?

Computers are bad at math. If you go into your friendly local Python terminal or JavaScript console, and type “0.1 + 0.1 + 0.1”, it will produce a number that is almost, but not quite 0.3. When you try to write programs that do math, things like this often happen. You may have heard that it’s because the number is “floating point.”

There’s a lot of superstition and folklore around floating-point numbers in computer science, plausibly due to occult-sounding terms like “mantissa” and “significand.” “Floating-point math is imprecise,” people will say. But the “floating-point” part gets way too much emphasis. “Math is too precise” is a better way to put it. The poor floating-point number is just chronically misunderstood.