Question

为什么我要“回归自我”;在课程结束而不是“返回0;”？这两个陈述有什么区别？

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    //Call the init method implemented by the superclass
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
       //Create two arrays and make the pointers point to them
       questions = [[NSMutableArray alloc] init];
       answers = [[NSMutableArray alloc] init];

       //Add questions and answers to the arrays
       [questions addObject:@"What is 7 + 7?"];
       [answers addObject:@"14"];

       [questions addObject:@"What is the capital of Vermont?"];
       [answers addObject:@"Montpelier"];

       [questions addObject:@"From what is cognac made?"];
       [answers addObject:@"Grapes"];

   }

   // Return the address of the new object
   return self;
}

@end

Answer 1

因为return 0;会返回NULL指针。不是人们期望成功执行的初始化程序（完全因为它应该返回它已初始化的对象 - 否则你将丢失该对象）。初始值设定项不是main()。

Answer 2

从技术上讲，当你想使用init函数时，就像这样

MyClass *foo = [[MyClass alloc] initFunction];

因此，如果返回0，则对象foo无法访问新创建的MyClass。

为什么init方法以＆＃34; return self;＆＃34;结束？而不是＆＃34;返回0;＆＃34;？

2 个答案: