objective c - When didReceiveMemoryWarning and applicationDidReceiveMemoryWarning is called? -

if both methods implemented didreceivememorywarning , applicationdidreceivememorywarning 1 called first, if memory low.

what difference between them?

the difference belong different interfaces. 1 application delegate, other uiviewcontroller. should both try release unneeded memory possible.

i don't think order guaranteed anywhere, consistent. set breakpoints or add log statements measure called first.