The JavaScript type coercion algorithm

So this is what insanity looks like.

So JavaScript type coercion is odd, but if you understand it and the WHY, it isn’t that bad.

Complain about this instead: https://jsdate.wtf/

To make it even worse

Javascript's type coercion is rather insane, yes, but there is an actual, practical reason it's done. JS, having been designed to be run in web browsers, wants to avoid blowing up and crashing at all costs. If it gets an unusual type comparison, usually the result of a bug, it tries to return something, such that the script can continue running if at all possible. In JS' mentality, keeping a page running, even if it might not completely function properly, is preferable to throwing an unhandled exception and completely crashing it.

Whether or not that is the right approach is debatable, but there is at least some logic to it. Personally, I think that the proliferation of Node letting JS run outside of browsers exacerbates a lot of JS' issues, but TypeScript does a lot to make it look like a more sensible language.

This makes it make so much more sense...

Its not really insanity, just a lot of hidden function calls

This is Haverbeke's book, right? Eloquent JavaScript?

Hey OP, do you mind checking if your book explains the type coercions that are used with the + operator? I remember it also being mind-boggling, so I was hoping you book could demystify it too.

I mean, it is the basic concept of truthiness. At least they let you use strict equal.

The description in the first photo about int - steing comparison is incomplete though, right? Wasn't there also a rule anout which one of then comes first (the second parameter gets converted?), and what happens if a string contains non-numeric values?

It's all so confusing…

But then why 2 == true if true is converted to 1

Is that a tear on the "again"?

why convert boolean to integer instead of converting the other operand to boolean? it doesn't make sense.

Hello from Perl! Looks reasonable to me!

Yes, we should all use rigid types. Name me one language you actually like writing quickly with that has types?

Pyth-oh. Bash-oh. Lisp-oh. Perl-oh. Oh yeah... typed languages suck because of all the boiler

Edit: Fine, Python / Lisp / Perl are all technically "typed" languages, but I ask you what's point of throwing type errors at runtime. Javascript and Rust actually have it right here that the code is either going to run, or it simply isn't. No pussyfooting letting it run first to throw complaints