NSMutableArray是零.为什么？

Question

我添加对象后,NSMutableArray它变成了nil(我检查了NSLog)

---

码

guests = [[NSMutableArray alloc]init];
guests = [localDictionary objectForKey:@"guestsArray"];

[guests addObject:@"1"];
[guests addObject:@"12"];
[guests addObject:@"31"];

if(guests == nil)
{
    NSLog(@"WHY?");
}

你知道为什么会这样吗？我该怎么检查？

Answer 1

这是因为[localDictionary objectForKey:@"guestsArray"]是零.