Eloquent JavaScript 4th edition (2024)

Yes, exceptions can have codes. As far as I have experienced, their error instances don't do anything better than a plain object, and a non-exception error object can more clearly take a wide variety of shapes. It also limits potential confusion between errors or exceptions raised by your code and that of some dependency.

It is true that exceptions "bubble", and plenty of developers take advantage of that behavior. In my opinion, it is not helpful for errors that are expected to happen as part of normal application behavior. Bubbling of errors creates a sense of logical indirection. Errors as return values communicate that likely nothing " wrong" actually happened. Good communication through code reduces the amount of time developers spend using the wrong assumptions when debugging.

There is also no reason why errors in a return value can't be returned by the caller. When you learn to love objects/hashes as return values, you can get the same benefits of bubbling but with a more clear path to follow when getting a picture of where a value is coming from and why.

In the case of actual exceptions, like accessing a property on undefined, an error being thrown is appropriate because, like you say, it can be bubbled up. The nice thing about reserving exceptions for this sort of thing is you might get away with a single try-catch at the highest scope and have a single straight forward error modal for when an unexpected problem occurs. Then you can otherwise implement errors in your code without the possibility that they will escape through bubbling and trigger behavior that is not immediately obvious when following the path of execution.

This is not to say that the tradition of using errors and try-catch for normal application control flow is inherently bad. Its just another tool. I do subjectively believe they are counter productive when used that way, and encourage others to try something like my approach. I think we would benefit by making it a standard practice.

Great book

Disclaimer: this is my own, metaphor-filled hypothesis.

It’s easy to fully internalize generalizations that someone has presented to you, usually because it’s wrapped up in a way that is mostly compatible with how you see the world. Because someone has done the work of distilling this information, you are not able to share in most of the intellectual benefit. It’s the process of having a question, discovering an answer, internalization of the concept, and synthesizing a summary that brings you closer to understanding. It feels like a series of “lightbulb moments” when we consume this content, but it is often shallow and fleeting because the genesis of the idea was not your own. Airport/self-help books are a good example of this mental candy that makes us feel good when reading it but, unless you are able to fully internalize it, are just empty mental calories.

Comprehension and understanding are derived from amassing knowledge a little bit at a time as your mind is ready to advance your understanding. In other words, you really have to be “primed” for knowledge found in books. This is the reason that information you obtain after an adequately-informed struggle stays so salient: your mental model had all the scaffolding around a concept but there was a clear “void” where this answer fits, and if you find that fits super cleanly, it’s extra satisfying.

When consuming information-dense material, you end up with this knowledge back-pressure where it’s floating around your short term memory but won’t be committed to long term memory because there is just no place for it yet. When recalling information in order to create new content with it, and assuming you are challenging yourself, you will end up in situations where there is information starvation (the opposite of back-pressure) where you must either find answers (to fit in your mental model) or find a workaround (ignore the gap).

Some people can just read books and create efficient mental models. Others (myself included) have a limit of how much they can learn in one sitting because our brains need to be fully ready to accept this information.

The last piece of this is the dopamine response cycle that is a positive feedback system (positive as in “more creates more”). Dopamine makes us feel good by rewarding behavior that evolution deemed necessary for species survival (over simplification). Dopamine indirectly triggers long term memory retention because we need to remember why we felt good in that moment so we can replicate it. This used to be, “this berry tastes good, I should remember where this bush was and what the berry looked like.” In the modern context, it ultimately delivers motivation to us because we have adapted to using it to learn new information that is less relevant to survival. Achieving goals and solving problems at hand causes a huge amount of dopamine release. The problem is that we’ve found ways to hijack these systems and short-circuit this feedback cycle so everything had to become way more stimulating.

This got long, but my advice is to work on a project of your choosing that you are intrinsically motivated to do. Begin work on that project and read some of the book that relates to the problem at hand. Repeat this cycle of reading and working, trying to incorporate patterns and concepts you find while reading into your project. Make little goals for yourself every day before your start, and really hold yourself accountable in finishing them.

I agree

I read about fifty books a year for a decade now. Only about four of them per year, are programming books. They are indeed to be read very differently. Here's how I read them, ymmv.

- never in bed. never as audiobook. But sitting. At a table or desk.

- no distractions. At most "focus music".

- read a chapter through. Then read it again and do all excercises (on a computer without wifi)

- make copious notes, highlight quotes, summarize. Most important for me is to write down why I made that note.

- a time (years sometimes) later, do it again. E.g. when having worked on the concepts from a book in real prod projects.

- at most an hour. I have ADHD and my mind often flies everywhere suddenly; time to give up and grab a beer or coffee.

Very few of these work as ebook (Kobo) for me. The formatting of code is poor and diagrams unreadable. Prefer paper or PDF (but read on a computer or tablet without network).