Some good iOS questions

这里，我列举了一些在Stackoverflow中一些比较好的关于iOS的问题。大部分我列举的问题都是关于Objective C。所有问题中，我比较喜欢“为什么”这一类型的问题。

问题

1. What’s the meaning of Base SDK, iOS deployment target, Target, and Project in xcode
2. const char* and char const* – are they the same?
3. Objective-C static, extern, public variables
4. UIView frame, bounds and center
5. What’s the difference between a string constant and a string literal?]

6. performSelector may cause a leak because its selector is unknown
7. How to write iOS app purely in C
8. How to tell if UIViewController’s view is visible
9. EXC_BAD_ACCESS signal received
10. When to use NSInteger vs. int
11. Why does Apple recommend to use dispatch_once for implementing the singleton pattern under ARC?
12. Custom dealloc and ARC (Objective-C)
13. How do I avoid capturing self in blocks when implementing an API?
14. Autoresizing masks programmatically Vs Interfact builder / xib / nib
15. How can I use NSError in my iPhone App?
16. iOS: How to store username/password within an app?
17. whose view is not in the window hierarchy
18. What are the Dangers of Method Swizzling in Objective C?
19. Differences between strong and weak in objective-c
20. Do I set properties to nil in dealloc when using ARC?
21. Where’s the difference between setObject:forKey: and setValue:forKey: in NSMutableDictionary?
22. Why would you use an ivar?
23. What does NSRunLoop do?

摘要

1、iOS tag on Stackoverflow