类方法也继承吗？

Question

当我定义一个继承自 NSObject 的新类时：

@interface Photo : NSObject
{
    NSString* caption;
    NSString* photographer;
}

@property NSString* caption;
@property NSString* photographer;

@end

NSObject中的所有类方法（如alloc）都被新类Photo继承了吗？

Answer 1

是的，当您继承 NSObject 时，Photo 可以使用 NSObject 的任何方法/属性/ivar/etc（声明为 @private 的那些 iVar 除外）：

Photo *myPhoto;
myPhoto = [[Photo alloc] init];
// ... Do some myPhoto stuff ...
NSLog(@"Photo object: %@", myPhoto);
NSLog(@"Photo description: %@", [myPhoto description]);
NSLog(@"Photo caption: %@", [myPhoto caption]);
NSLog(@"Photo photographer: %@", [myPhoto photographer]);

更多关于@private -> SO Question: what-does-private-mean-in-objective-c

NSObject Class Reference