Stack Overflow has reams of bad advice for Objective C. The dominant suggestions (that I encounter, anyway) routinely come up at the next-year's WWDC as things you should not ever do for any reason (and then they continue to be the dominant suggestion for another year).
Not that there isn't a lot of good, free resources out there. Apple's documentation being the most important and valuable example. But someone has to fill in the gaps, and I will happily argue that it can be worth quite a lot of time and money to learn something correctly rather than waste many hours due to bad advice. I haven't looked through these in particular, but yes, people pay for things like this, and they can definitely be worth it.
"Stack Overflow has reams of bad advice for Objective C. The dominant suggestions (that I encounter, anyway) routinely come up at the next-year's WWDC as things you should not ever do for any reason (and then they continue to be the dominant suggestion for another year)."
Not that there isn't a lot of good, free resources out there. Apple's documentation being the most important and valuable example. But someone has to fill in the gaps, and I will happily argue that it can be worth quite a lot of time and money to learn something correctly rather than waste many hours due to bad advice. I haven't looked through these in particular, but yes, people pay for things like this, and they can definitely be worth it.