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Comment by mrskitch | Hacker News Reader

My sentiment here is that modern JavaScript is _much_ better than its predecessors. The real issue, as it pertains to the web browser, is supporting legacy functionality that's causing drag on the web as a whole.

I'm curious: what's so bad about JavaScript that other languages seem to do better?

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The implicit type coercion of JavaScript is terrible, the single-inheritance prototype system is awful, lack of integer types, and undefined.

NaN is the ultimate horror within JavaScript's type system.

Other than that, you're spot-on.

or undefined and null. I mean most languages have "problems" with null, but JS basically has two "problems".

NaN behaves as it does in any other language with IEEE 754 floats (the behaviour of NaN simply comes from IEEE 754), which is most…?

> NaN behaves as it does in any other language with IEEE 754 floats

Yes, but most other languages don't use IEEE 754 binsry floating point as their only numeric type. Or even their primary one.

While I dislike NaN and would much rather prefer an exception to be thrown, I can accept NaNs existence because it's at least part of the IEEE 754 standard. It still bugs me that `NaN != NaN`, and JavaScript's type coersions make NaN worse because it seems like they randomly popup.

How many times have NaN semantics actually broken your code? My guess is never.

Single inheritance prototype system is actually something I like about js. I'm wondering why you consider it awful?

It's too ad-hoc and over-complicated to implement common things such as classes and interfaces. In JavaScript you're essentially stuck with stringly typed values and chaining mix-ins together to emulate a class hierarchy. It's also difficult to get instanceof to work as one would expect. The other languages I'm used to all natively support it: Python and Java. Granted, Java is single-inheritance too but you can implement multiple interfaces.

Ah yes if you're thinking in terms of classes then that would be frustrating.

Even with the most ubiquitous language in the world using prototypical inheritance, the average (mean) programmer prefers to imagine and express themselves in an inheritance based system. At some point, everyone will have to accept that prototypical approach is fine for some, but less productive over time for the world.

The type system and standard library.

The standard library is improving a lot.

> The standard library is improving a lot.

Javascript has next to no standard lib, actually. Let's not forget that the DOM or WebAPI are not part of ECMAScript spec.

What do you think it needs?

It still doesn't have integers.

Not having numeric types is a real issue - but on the plus side BigInt is advancing quickly https://github.com/tc39/proposal-bigint

Agreed. The fact that JavaScript lacks reasonable numeric types means that I never use it except when there is no alternative.

I miss true integers! And literally almost every other type. I'm looking forward to trying out typescript, but it would be nice if this was a part of the pure language itself

https://github.com/tc39/proposal-bigint/blob/master/README.m...

I wasn't aware of this. This is awesome! Thank you

No standard library hurt for a long time.

Javascripts handling of asynchronous operations.

What’s wrong with that exactly?

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