为什么在释放后设置为nil? [英] Why setting to nil after releasing?
问题描述
我遇到了这个方法:
-(void) someMethod {
NSMutableArray *anArray = [[NSMutableArray alloc] init];
// Do stuff with anArray ...
[anArray release];
anArray = nil;
}
将数组设置为nil?
这个代码通过发送一个释放消息到数组,它会导致数组被释放。
Is setting the array to nil necessary?
In this code by sending a release message to the array, it will causes the array to be deallocated.
推荐答案
在这种情况下,这是对关键笔划的无意义浪费,因为变量anArray会立即超出范围。
In this case, it is a pointless waste of key strokes because the variable anArray goes out of scope immediately.
在其他情况下,变量在释放指向的对象后仍然保持一段时间,这是一个好主意,因为如果您不小心解除引用,你会得到一个容易发现的EXC_BAD_ACCESS,如果你发送一个消息,它将被忽略(除了返回nil / 0)。
In other cases, where the variable stays in scope for a while after you release the object its pointing to, it is a good idea, because, if you accidentally dereference it, you will get a EXC_BAD_ACCESS which is easy to spot, and if you send a message to it, it will be ignored (except for returning nil / 0).
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