this post was submitted on 16 Jun 2023
87 points (100.0% liked)

Programmer Humor

32710 readers
661 users here now

Post funny things about programming here! (Or just rant about your favourite programming language.)

Rules:

founded 5 years ago
MODERATORS
 
top 23 comments
sorted by: hot top controversial new old
[–] [email protected] 11 points 2 years ago (2 children)

Ok some of these I understand but what the fuck. Why.

[–] Daniikk1012 13 points 2 years ago

a >= b, is equivalent to, !(a < b)

[–] [email protected] 6 points 2 years ago (2 children)

I'm not sure if you really want to know, but:

greater than, smaller than, will cast the type so it will be 0>0 which is false, ofcourse. 0>=0 is true.

Now == will first compare types, they are different types so it's false.

Also I'm a JavaScript Dev and if I ever see someone I work with use these kind of hacks I'm never working together with them again unless they apologize a lot and wash their dirty typing hands with.. acid? :-)

[–] [email protected] 8 points 2 years ago* (last edited 2 years ago)

isn't === the one that compare types first?

I just tried on node and 0 == '0' returns true


found the real reason

[–] [email protected] 1 points 2 years ago (1 children)

Not a JavaScript dev here, but I work with it. Doesn't "==" do type coercion, though? Isn't that why "===" exists?

As far as I know the operators ">=" and "<=" are implemented as the negation of "<" and ">" respectively. Why: because when you are working with sticky ordered sets, like natural numbers, those operators work.

Thus "0<=0" -> "!(0>0)" -> "!(false)" -> "true"

Correct me if my thinking is wrong though.

[–] [email protected] 1 points 2 years ago

So will null <= 0 returns true?

Why tho

[–] [email protected] 8 points 2 years ago (1 children)

I know it’s a joke, but it’s an old one and it doesn’t make a lot of sense in this day and age.

Why are you comparing null to numbers? Shouldn’t you be assuring your values are valid first? Why are you using the “cast everything to the type you see fit and compare” operator?

Other languages would simply fail. Once more JavaScript greatest sin is not throwing an exception when you ask it to do things that don’t make sense.

[–] [email protected] 3 points 2 years ago (1 children)

Shouldn’t you be assuring your values are valid first?

Step 1: Get to prod

Step 2-10: Add features

Step 11: Sell the company before it bites you

[–] [email protected] 1 points 2 years ago

As a professional bite-mean-for-other-guy taker (right now in Java) this hurts my feelings.

[–] [email protected] 7 points 2 years ago* (last edited 2 years ago) (1 children)

This one is one of my favourite JS quirks:

JS quirk

[–] [email protected] 0 points 2 years ago (1 children)

Wait wtf is happening there?

[–] [email protected] 2 points 2 years ago

parseInt is meant for strings so it converts the number there into a string. Once the numbers get small enough it starts representing it with scientific notation. So 0.0000001 converts into "1e-7" where it then starts to ignore the e-7 part because that's not a valid int, so it is left with 1

https://javascript.plainenglish.io/why-parseint-0-0000001-0-8fe1aec15d8b

[–] [email protected] 4 points 2 years ago

I wrote an exam about this stuff yesterday.

In J's equality is usually checked in a way that variables are casted to the type of the other one. "25" == 25 evaluates to truey because the string converted to int is equal to the int and the other way around.

You can however check if the thing is identical, using "25" == 25 which skips type conversion and would evaluate as false.

I assume the same thing happens here, null is casted to int, which gets the value 0.

[–] [email protected] 3 points 2 years ago
[–] [email protected] 2 points 2 years ago

I had a fun bug where unit tests started failing on an upgrade. Turns out someone was returning undefined from a comparator. Wtf, people.

[–] [email protected] 1 points 2 years ago
[–] [email protected] 1 points 2 years ago

Is there a JS joke out there that doesn't have to do with type coercion?

[–] [email protected] 1 points 2 years ago (2 children)

Can someone explain this? I mean, the last result. Usually I can at least understand Javascript's or PHP's quirks. But this time I'm stumped.

[–] [email protected] 4 points 2 years ago* (last edited 2 years ago) (1 children)

JS null and undefined shenanigans


basically:

  1. bigger an lesser comparison types convert null to zero, so is zero bigger than zero? no
  2. == is fucky and to it null only equals undefined and undefined only equals null, so no
  3. is zero bigger than or equal to zero? yeah
[–] [email protected] 0 points 2 years ago (1 children)

Ugh, thanks, of course. Stupid brain.

[–] [email protected] 1 points 2 years ago (1 children)

I'm starting to think JS maintainers have a thing against mathematicians

[–] [email protected] 1 points 2 years ago

more likely against humans

[–] [email protected] 2 points 2 years ago

My only thought here might be >= is usually the same as !< and maybe thats how it is defined in javascript and since < is false than >= == !false == true

load more comments
view more: next ›