0.1 + 0.2 == 0.3 returns false in all the interpreters I have installed locally (Ruby, Python, NodeJS and Haskell), and you can't with a straight face pretend that Haskells type system is not strict enough.

Because I was curious, I tested it out with C# on repl.it and behold, 0.1 + 0.2 == 0.3 returns false in C# as well: https://repl.it/repls/AdoredValidVirtualmachines. Not very surprising of course, since that "error" is a result of the IEEE floating point spec and not of any language.

Thank you, I'm so sick of this being used as an example of why JavaScript is bad...

If you write in C# decimal a = 0.1m; decimal b = 0.2m; var result = a + b; then you will get exactly 0.3, because decimal is a special high-precision numeric type that doesn't have such issues.

It's not just JavaScript with that issue... https://0.30000000000000004.com/

Not if you use decimal type that is not available in JavaScript.

I'm curious what you're comparing JavaScript to. Decimal is the native numeric datatype for the stored procedure language of the database I use. Otherwise, even in languages that have a decimal class in their standard library, it's usually pretty clunky to use; no better than, say, https://github.com/MikeMcl/decimal.js/ C# is perhaps the best among mainstream languages, although its implementation is a bit weird.

What is clunky about decimal type? You declare a decimal variable and then use it exactly like any other numeric type. Here is an example: https://dotnetfiddle.net/jjJHA6