为什么建议将_weak引用与委托一起使用

Question

Hi every one whether some one will elaborate me that why it is recommended to use the _weak reference for delegates and not the strong reference? though we can also use the strong reference for delegates. Some one will please tell me with the better and descriptive example with simple way that in which situations should we use the strong reference and in which situations should we use the _weak reference for the delegates.

I went through one of the related question on stack overflow

Is it ever Ok to have a 'strong' reference for a delegate?

but it did not clear my concept properly.

Any help will be highly appreciated !!

Thanks.

Answer 1

Using __strong on delegate is very easy to create retain cycle:

say A has a strong reference to B, and some object set A as a delegate of B, if the delegate is strongly referenced, then, a retain cycle is formed.

Answer 2

Yes, It's east to creat a retain cycle while using __strong on delegate.

Addtionally, in ARC, we using weak on delegate，while the object using the delegate is released，the delegate will be nil automatically.