NSMutableArray的奇怪行为

Question

以下是我的应用程序中的代码：

NSMutableArray *firstPhotoVoters = post.firstPhotoVoters;
NSMutableArray *secondPhotoVoters = post.secondPhotoVoters;

ALog(@"First voters: %@", firstPhotoVoters);
ALog(@"Second voters: %@", secondPhotoVoters);

for (Post* _post in posts) {
    if ([_post.objectId isEqualToString:post.objectId]) {
        [_post.firstPhotoVoters removeAllObjects];
        [_post.secondPhotoVoters removeAllObjects];

        ALog(@"Count: %d", firstPhotoVoters.count);

        ALog(@"Updated post: %@", _post);
    }
}

两个ALog语句（NSLog的宏）转储firstPhotoVoters和secondPhotoVoters数组中存在的数组元素。但是，在for循环中，两个数组看起来都是空的。 firstPhotoVoters.count始终为零。我在这里缺少什么？

谢谢。

Answer 1

你刚刚清空了数组然后你就记录了它。它应该在if语句之外。