3.Difference between categories and extensions? 类别和类扩展的区别。 答案:category和extensions的不同在于 后者可以添加属性。另外后者添加的方法是必须要实现的。 extensions可以认为是一个私有的Category。 &a是数组指针,其类型为 int (*)[5]; 而指针加1要根据指针类型加上一定的值,不同类型的...
However, if you do want compile-time type checking, you must decide between the second and third cases. Well, let me just help you out—you want the third case! :-) I've very, very, VERY rarely seen a situation whereNSObject *worked butid<NSObject>would not. And using the protocol...
@property(nonatomic, retain)NSString*name; @property(nonatomic, retain)NSArray*items; in the iPhone world, there's no garbage collector available. You'll have to carefully manage memory with reference counting. With that in mind, consider the difference between: name =@"Test"; and self.name ...
= nil) { return [NSAppleEventDescriptor descriptorWithProcessIdentifier:runningApp.processIdentifier]; } return nil;}- (NSAppleEventDescriptor*) appleEventForOpeningFileAtPath:(NSString*)filePath withApplicationBundleID:(NSString*)appBundleID displayingCustomPathString:(NSString*)customPathString{ NSApp...
The transformer does not provide reverse transformations; you can only transform from an NSDate to an NSString. How To Use Add the source files and localized strings bundle to your project. SORelativeDateTransformer.h SORelativeDateTransformer.m SORelativeDataTransformer.bundle Create an instance of...