Question

I am used to have this in my code

myClass.h

@property ( strong, nonatomic ) ClassA *varA

myClass.m

varA  = [[ClassA alloc] init];
if ( varA isEqual:nil )
   NSLog@"var A is nil");
else
   NSLog@"var A is not nil");

this is a result from console

var A is not nil

I thought var A should be nil then. So my question is what does blue line do and why var A is not nil after all

Answer 1

You just allocated varA, then you have a ClassA object, you didn’t release it or setting it to nil, so why did you expect it to be nil?

It’s normal behaviour, it’s like you just made (alloc) yourself a nice cup of coffee, if you didn’t drink/throw (release or setting it to nil) your coffee should still be there, right?