__weak UIDataType * weakSelf和UIDataType __weak * weakSelf之间的区别？

Question

I'm seeing two different implementations...

__weak UIDataType *weakSelf = self;

and

UIDataType __weak *weakSelf = self;

Yet they both seems to work. Is there a difference in terms of what happens under the hood?

Thanks in advance for your wisdom!

Answer 1

There is no difference. Since __weak can only apply to pointer-to-object types, the compiler recognizes that there is only one meaning that makes sense for all of the following:

__weak UIDataType *weakSelf;
UIDataType __weak *weakSelf;
UIDataType * __weak weakSelf;

The same applies to the other ownership qualifiers ( __strong , __autoreleasing , etc.)

If you're comfortable reading technical specifications of programming languages, you can read more about it here: http://clang.llvm.org/docs/AutomaticReferenceCounting.html#spelling .