r~~‭ please read the following thread and say there if you agree with elgonzo

https://software.codidact.com/comments/thread/6233

I didn't see the comments that were deleted in that thread, but in my opinion elgonzo's initial comment is absolutely correct, both with respect to the facts of the matter and with respect to the advice that ought to be given to a junior JavaScript developer who posted the code you did.

With respect to this question and answer, don't get too hung up on the fact that elgonzo mentioned BNF. The convention of square brackets to denote optional elements is present in some variants of BNF, but not most; and I've seen that convention used in much documentation that otherwise has nothing in common with BNF. It's a questionable choice to use it where it could be confused with a JavaScript array, but the library author presumably expected a JavaScript developer to immediately recognize that line as invalid JavaScript and to reach for more creative interpretations.

r~~‭ I don't understand, do you think that I don't understand JavaScript fundamentals just because I didn't recognize that this was pseudocode?

Furthermore, now I do know that this was brackets pseudocode and have learned to recognize such pseudocode (call it BNF or otherwise) so by that logic now I do know the fundamentals of JavaScript syntax.

Frankly, yes, it is evident that you are still learning JavaScript. There's nothing wrong with that—we're here on this site to learn and to help others learn! And you're right that you will eventually master the language by making mistakes and remembering what you learn from them. But don't be over-confident and assume that your most recent mistake is the last one you needed to make before reaching mastery. Nobody here is interviewing you for a job; you have nothing to prove to anyone except yourself. Which will help you learn more, humility or defensiveness?

The clues that tell me that the line is pseudocode have nothing to do with the brackets, by the way. Do you know what they are?

r~~‭ I am not a JavaScript master or expert, but I disagree that I don't know the fundamentals of JavaScript syntax because I know what is assignment, comparison, variable, procedure, array, object, property, method, setTimeout(), setInterval() etc. are and have written many JavaScript codes which just work:

https://github.com/benaharoni/javascript

const iframes = iFrameResize() AND the brackets tell me this is a pseudocode.

Looks like a nice set of notes. When you have learned JavaScript, you will be able to do more than enumerate things that you have gotten to work; you will also be able to explain why something doesn't work.

There is nothing invalid or pseudocode-ish about const iframes = iFrameResize(). That could easily be actual code. So can the brackets; as you surely know, square brackets are used in actual code to express array literals.

The clues that tell me that the mentioned line is not actual JavaScript are the following:

• css selector—there is no JavaScript syntax that allows two words, outside of a string literal, to appear next to each other with no punctuation between them, unless one of the words is a keyword (which neither css nor selector is).

• [css selector] || [iframe]—taken literally, and ignoring the previous issue, this is the or-ing of two array literals, which is valid syntax but nobody would ever do it in real code. Arrays are always truthy, so the second array would never matter.

These specific clues are not facts that JavaScript developers memorize; they are instead straightforward consequences of the fundamentals of syntax and the logic primitives, which JavaScript developers do memorize. You should ask yourself why you missed both of them, if you know everything you claim to know.

r~~‭ I can explain why something doesn't work to some extent.

I agree that I missed the issue about css selector but that's because I just copy-pasted the file without deepening in in.

I didn't understand the second thing you wrote about arrays, what will people never do in real life coding?

r~~‭ I misunderstand why the fact that array is always truthy, should hinder any attempt to pass two or more arrays as arguments.

Comments aren't for extended conversation. If you have more questions about JavaScript that aren't duplicates of your previous questions, and you can make the effort to make them good questions (i.e., you've researched them elsewhere, you've experimented on your own, you've read any relevant error messages, and you can clearly state what it is you still need help with) please make new posts and I or someone else will be happy to answer there.

I will leave this community for good today. I thank you for pointing out that I lack only some or most JavaScript fundamentals, but not all. I greatly respect that.

Goodbye and all best.