0.30000000000000004 VS wtfjs

https://0.30000000000000004.com/

Although it would be good to move in the direction of using a BigDecimal equivalent by default when ingesting unknown data.

There's no such thing as precision for floats. Floating-point calculations are always inaccurate: read this: https://0.30000000000000004.com/

Edit: This specific example even has its own website: https://0.30000000000000004.com/

In everyday math, we know adding 0.6 + 0.3 equals 0.9, right? But when we turn to computers it results in 0.8999999999999999. Surprisingly, this doesn’t just happen only in JavaScript; it’s the same in many programming languages like Python, Java, C too. Also, it’s not just about this specific calculation. There are many more decimal calculations showing similar not-quite-right answers.

Surprisingly common values like 0.1 don't have a precise representation in binary for most formats, including standard floating point number formats. See https://0.30000000000000004.com/ for more detail than you can shake a stick at.

Also if the local tax code states using 5 decimal places for intermediate values when you will introduce “errors” using formats that give greater precision as well as those that give less precision. Having work on mortgage and pension calculations I can state that the (very) small errors seen at individual steps because of this can balloon significantly through repeated calculations.

Furthmore, the name floating point gives away the other issue. Floating point numbers are accurate to a given number of significant figures not decimal places. For large numbers any decimal places you have in the result are at best an estimate, and as above any rounding errors at each stage can compound into a much larger error by the end of a calculation.

You'll love this https://0.30000000000000004.com/

Me in the interview: "Generally, no, a variable can only be assigned one numeric value at a time. However, Javascript is famous for unpredictable behaviors in variable comparison statements, for instance [] == ![]. There's actually a whole library built around documenting this type of behavior this for comedic value, and other more serious libraries geared towards solving the problem. So it's possible that some obscure variable assignment scenario would result in that line evaluating as true, but it's not something you'd expect to encounter in the real world. This has gotten a lot better with typescript and es2022, but still something you need to watch for a bit."

I do see that point of view, didn't think of that, there are some aspects of go which are a bit weird if you never touched lower abstraction languages, yet once you learn what they are, you are all set and you can code in anything. go has the least amount of gotchas I have seen in any programming language. compare it with loads of the weird stuff javascript does https://github.com/denysdovhan/wtfjs and go is like heavenly lol

Its a very poorly designed language. Its syntax and semantics are often confusing and unpredictable. There is no well defined mental model of how constructs work in this language.

WTF JS

😎 A great guide to Javascript that is both simple and wonderful, but also difficult and fun that seems like bullshit. -> wtfjs