共有三个类Question
,Choice
and Blank
,and是andQuestion
的超类。Choice
Blank
然后,我写了一些方法如下:
- (instancetype)initWithQuestionType:(NSString *)questionType
{
NSLog(@"**class:%@",[self class]);
if([self isMemberOfClass:[Question class]])
{
self = nil;
if([questionType isEqualToString:@"choice"])
{
NSLog(@"--class:%@",[self class]);
self = [[Choice alloc] initWithQuestionType:questionType];
NSLog(@"++class:%@",[self class]);
}
else
{
self = [[Blank alloc] initWithQuestionType:questionType];
}
return self;
}
return [super init];
}
- (instancetype)init
{
NSLog(@"Init!");
return [self initWithQuestionType:@"unKnow"];
}
进而:
Question *question = [[Question alloc] initWithQuestionType:@"choice"];
输出为:</p>
2015-10-16 20:58:50.278 initSample[3687:161396] **class:Question
2015-10-16 20:58:50.279 initSample[3687:161396] --class:(null)
2015-10-16 20:58:50.279 initSample[3687:161396] **class:Choice
2015-10-16 20:58:50.280 initSample[3687:161396] ++class:Choice
我不明白为什么[super init]
没有被处决?