ios - autoreleasepool中第一个用工厂方法创建的对象会在最后被释放？

Question

初学者，一直没搞懂ARC模式下autoreleasepool对象释放的问题，后来发现autoreleasepool中第一个用工厂方法创建的对象会在最后被释放，不知道是不是这样？还是我哪里搞错了？所以。。为什么会出现这样的输出呢？

似乎只有第一个autoreleasepool会这样，后面的包括嵌套的autoreleasepool都不会出现这个问题。

代码如下，NSMutableArray和NSMutableDictionary都重写了dealloc方法。

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        NSMutableDictionary *dict=[NSMutableDictionary dictionaryWithCapacity:10];
        NSMutableArray *array1=[NSMutableArray arrayWithCapacity:10];
        NSMutableArray *array2=[NSMutableArray arrayWithCapacity:10];
        __unused NSMutableArray *array3=[NSMutableArray arrayWithCapacity:10];
        dict = nil;
        array1 = nil;
        NSLog(@"------------");
        array2 = nil;
        NSLog(@"continue......");
    }
    NSLog(@"After AutoReleasePool");
    return 0;
}

输出结果：

2016-03-03 22:44:25.452 ARC[13973:3216802] NSMutableArray released
2016-03-03 22:44:25.453 ARC[13973:3216802] ------------
2016-03-03 22:44:25.453 ARC[13973:3216802] NSMutableArray released
2016-03-03 22:44:25.453 ARC[13973:3216802] continue......
2016-03-03 22:44:25.454 ARC[13973:3216802] NSMutableArray released
2016-03-03 22:44:25.454 ARC[13973:3216802] NSMutableDictionary released
2016-03-03 22:44:25.454 ARC[13973:3216802] After AutoReleasePool
Program ended with exit code: 0

Answer 1

Can the dealloc method of NSMutableArray and NSMutableDictionary be overridden? It means no.