Serious question - has Javascript the language evolved any features for handling integer math correctly so expressions like 2*57 aren't silently rounded? I realize that in most cases Javascriopt is "good enough" for useful work but I've seen even senior engineers get tripped up by Javascript's corner cases when it comes to its handling of integer vs float.
Eloquent JavaScript 4th edition (2024)
21–30 of 249 posts
Re: Eloquent JavaScript 4th edition (2024)
#22What's new in this edition?
It should be mentioned in the "Introduction" but it seems your question is not covered there.
Re: Eloquent JavaScript 4th edition (2024)
#23Serious question - has Javascript the language evolved any features for handling integer math correctly so expressions like 2*57 aren't silently rounded? I realize that in most cases Javascriopt is "good enough" for useful work but I've seen even senior engineers get tripped up by Javascript's corner cases when it comes to its handling of integer vs float.
There's BigInt [0]. Probably less useful for this specific case, but possibly useful as well, are typed integer arrays [1].
[0] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...
[1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guid...
Re: Eloquent JavaScript 4th edition (2024)
#24This is my favorite book about JS, and I always recommend it to people. It occurs to me for the first time that the lack of TypeScript might be a problem, because if I’m making recommendations to someone learning, I am definitely going to recommend they write TS instead of JS. On the other hand it may actually be helpful to learn the concepts in this book without the additional syntax overhead of type annotations, pl…
It is useful to know vanilla JS. Right now I am learning an integration platform that uses JS for its scripting language, but you cannot use TS.
Re: Eloquent JavaScript 4th edition (2024)
#25Earlier quoted context omitted.
I very much concur that it is better NOT to introduce TS when explaining JS fundamentals. I've seen smart engineers with a C++ background get tripped up on and very confused working with TS, because it's not clear to them what concepts are "language fundamentals" and what concepts are "the TS transpiler". (Like expecting that just because you declared something as type X, that it guarantees at runtime it will always…
What helped me understand the Runtime behaviour of TS is to understand that TS doesn't actually have strong typing. If it was named "LintScript", its name would be much closer to the truth.
This statement is quite questionable starting from the fact that there is no definition for what strong typing is.
Care to provide what you mean?
Strict TS won't compile pretty much any type-unsafe operation.
It's not perfect, the standard libraries are a bit too unsafe type wise, exceptions are untyped and need Either/Result-like data types to be handled but it's an extremely powerful language if you know it and it's ecosystem.
Most people though don't even bother reading the docs and can't tell you what a mapped type is or what is a disjointed union, etc.
Re: Eloquent JavaScript 4th edition (2024)
#26Earlier quoted context omitted.
I very much concur that it is better NOT to introduce TS when explaining JS fundamentals. I've seen smart engineers with a C++ background get tripped up on and very confused working with TS, because it's not clear to them what concepts are "language fundamentals" and what concepts are "the TS transpiler". (Like expecting that just because you declared something as type X, that it guarantees at runtime it will always…
Agree. I wish tools like zod/valibot were first class in typescript.
Also effect schema if you're looking for something much more powerful and in effect-land.
Re: Eloquent JavaScript 4th edition (2024)
#27Serious question - has Javascript the language evolved any features for handling integer math correctly so expressions like 2*57 aren't silently rounded? I realize that in most cases Javascriopt is "good enough" for useful work but I've seen even senior engineers get tripped up by Javascript's corner cases when it comes to its handling of integer vs float.
> handling integer math correctly
JavaScript doesn't have integers. Everything is a float. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...
Although it has BigInt now.
Re: Eloquent JavaScript 4th edition (2024)
#28This is my favorite book about JS, and I always recommend it to people. It occurs to me for the first time that the lack of TypeScript might be a problem, because if I’m making recommendations to someone learning, I am definitely going to recommend they write TS instead of JS. On the other hand it may actually be helpful to learn the concepts in this book without the additional syntax overhead of type annotations, pl…
I very much concur that it is better NOT to introduce TS when explaining JS fundamentals. I've seen smart engineers with a C++ background get tripped up on and very confused working with TS, because it's not clear to them what concepts are "language fundamentals" and what concepts are "the TS transpiler". (Like expecting that just because you declared something as type X, that it guarantees at runtime it will always…
> I've seen smart engineers with a C++ background get tripped up on and very confused working with TS, because it's not clear to them what concepts are "language fundamentals" and what concepts are "the TS transpiler".
This is exactly why I never recommend TypeScript to new developers.
A similar problem (that used to be worse) with people learning JavaScript is the lack of separation between JavaScript and the DOM + browser APIs. 10+ years ago, people have told me how much they hated JavaScript and when probed about it further, would admit that it’s actually the DOM or new/inconsistent browser APIs that have caused issued.
JS has a number of its own flaws and quirks, yes, but there are two fundamental issues that make it harder to approach as a new learner (as opposed to, to say, Python) are how tightly coupled it has historically been to it’s primarily application case and how high or low level is this language?
Re: Eloquent JavaScript 4th edition (2024)
#29Serious question - has Javascript the language evolved any features for handling integer math correctly so expressions like 2*57 aren't silently rounded? I realize that in most cases Javascriopt is "good enough" for useful work but I've seen even senior engineers get tripped up by Javascript's corner cases when it comes to its handling of integer vs float.
There's BigInt [0]. Probably less useful for this specific case, but possibly useful as well, are typed integer arrays [1]. [0] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe... [1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guid...
Ah, very cool. Thanks.
Re: Eloquent JavaScript 4th edition (2024)
#30Earlier quoted context omitted.
Because TypeScript is the de facto standard way of writing JavaScript for most of the industry and it has killed all of the other compile-to-js languages. The chances of it going out of favour are very slim, there's a giant ecosystem built on it and the language is very well loved by devs (should be second only to Rust). Microsoft has 50 people on payroll working only on TS. Any competitor needs a gargantuan investme…
And JavaScript has a bigger ecosystem and more entrenchment, not to mention an international standard.
and not to mention terrible.