Programming Horror

1872 readers

1 users here now

Welcome to Programming Horror!

This is a place to share strange or terrible code you come across.

For more general memes about programming there's also Programmer Humor.

Looking for mods. If youre interested in moderating the community feel free to dm @Ategon@programming.dev

Rules

Keep content in english
No advertisements (this includes both code in advertisements and advertisement in posts)
No generated code (a person has to have made it)

Credits

Icon base made by Lorc under CC BY 3.0 with modifications to add a gradient

founded 1 year ago

MODERATORS

Vacant@programming.dev

God I wish there was an easier way to do this (programming.dev)

submitted 11 months ago* (last edited 11 months ago) by andioop@programming.dev to c/programming_horror@programming.dev

25 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] lysdexic@programming.dev 1 points 11 months ago (3 children)

Divide by 2 and check for a decimal point.

I mean, it ain't wrong.

[–] Chobbes@lemmy.world 1 points 11 months ago (2 children)

You know, I was going to let this slide under the notion that we're just ignoring the limited precision of floating point numbers... But then I thought about it and it's probably not right even if you were computing with real numbers! The decimal representation of real numbers isn't unique, so this could tell me that "2 = 1.9999..." is odd. Maybe your string coercion is guaranteed to return the finite decimal representation, but I think that would be undecidable.

[–] backgroundcow@lemmy.world 1 points 11 months ago (1 children)

Ackchyually-- IEEE 754 guarantees any integer with absolute value less than 2^24 to be exactly representable as a single precision float. So, the "divide by 2, check for decimals" should be safe as long as the origin of the number being checked is somewhat reasonable.

[–] Chobbes@lemmy.world 1 points 11 months ago

Of course, but it's somewhat nasty when all of a sudden is_even doesn't do what you expect :).