局部变量默认为强还是弱？

Question

Lets say I have local variable(not property) Obj *x = d, is d's reference count incremented? Or is it default a weak reference?

Answer 1

Apple's documentation ( Variable Qualifiers section) said:

https://developer.apple.com/library/ios/releasenotes/ObjectiveC/RN-TransitioningToARC/Introduction/Introduction.html

__strong is the default. An object remains “alive” as long as there is a strong pointer to it.

Answer 2

Say you write

__weak NSMutableArray* myArray = [[NSMutableArray alloc] init];

What happens? What happens is that the only reference to that array is in a weak variable, which means it gets deallocated immediately and myArray is set to nil. Now say you write

NSMutableArray* myArray = [[NSMutableArray alloc] init];

What would happen if the default is "weak"? Does that answer your question?

Answer 3

They are strong by default.

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