How Objective-C messaging works

http://danie.lt/blog/2013/08/03/how-objective-c-messaging-works/

30 23 13 years ago

austinz• 13 years ago

What is "0xreadbook" in the context of a 32-bit int supposed to mean? Is the author just trying to be cute, or is this some sort of nonstandard representation of hexadecimal digits that I need to read up on?

orta• 13 years ago

It's the author being cute I think. I've never heard of it either.

tdd12• 13 years ago

Yes dude,

it just an example hexadecimal representation. Don't take everything so literally...

aa07• 13 years ago

Literally? A tutorial for noobs should be literally accurate -- throwing around non-proper representations is just a cloudy lazy explanation.

taspeotis• 13 years ago

it just an example hexadecimal representation

It's not hexadecimal, so what's your point?

aa07• 13 years ago

0xreadbook is not hexedecimal and disqualifies this whole post from any kind of intellectual redemption.

Try 0xDEADBEEF,0xBAADF00D, or any constant listed here: http://en.wikipedia.org/wiki/Hexspeak

tomjakubowski• 13 years ago

I'd probably avoid 0xB16B00B5.

aa07• 13 years ago

I'd probably multiply and sum...

pohl2• 13 years ago

That's a bit overpedantic. It's a mnemonic for remembering the way the bytes are arranged in memory: "Ok, Bo: add re".

Nobody complains that r, o, y, g, b, i, and v aren't actual colors, do they? Other than you, I mean.

http://en.wikipedia.org/wiki/List_of_mnemonics

aa07• 13 years ago

r=red, o=orange, y=yellow, etc.. No problem there.

What does K equal in hexadecimal? Well, it isn't defined for hexadecimal. K=20 is only defined in Base 21 and above.

Other than me? Hah, nice cheap shot, pole ;-)

nonchalance• 13 years ago

I stopped reading when I saw `i = 0xreadbook` and `typdef`. There are typos and there are fundamental misunderstandings -- not sure where these lie

rsingla• 13 years ago

Well at least the 16 year old tried?

archagon• 13 years ago

Hey man, that's kind of mean.

glhaynes• 13 years ago

Don't do that. Criticize people on their work, not on their personal attributes.

stevejohnson• 13 years ago

Try these if you'd like an actual explanation of how Obj-C messaging works.

http://www.mikeash.com/pyblog/friday-qa-2012-11-16-lets-buil...

http://www.friday.com/bbum/2009/12/18/objc_msgsend-part-1-th...

chromejs10• 13 years ago

I agree. This post isn't the best explanation and is riddled with grammatical errors that caused me to reread sentences multiple times. Regardless of the age of the author, if you put up a blog post that is supposed to explain a concept to other people, it needs to be well thought out and proof read.

Mike Ash is an excellent example of how to write blog posts about how things work

dmishe• 13 years ago

Also, Mark Dalrymple series http://blog.bignerdranch.com/author/markd/

How Objective-C messaging works

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