Objective-C blocks - does block retain the object it references?

Question

If I am using a block when making an asynchronous operation and the block references objects and properties of the view controller, does the block retain them and thereby making the view controller not get deallocated if the user leaves the view controller before the async operation ends?

Answer 1

Yes. Blocks are Objective-C objects and will retain any referenced objects. You can ask them not to, of course.

See: http://thirdcog.eu/pwcblocks/#objcblocks