When is if (!someObject) (short for someObject != nil) NOT safe?

Question

Possible Duplicate:
is there a difference between (!object) and (object == nil)?

In iOS (Objective C) development, I've frequently seen (and used) the following short hand:

if (someObject)
{
    // do something
}

To check that someObject is not nil.

In other words, to mean the same as the following:

if (someObject != nil)
{
    // do something
}

Are these two if statements actually the same or is this not safe?

Maybe... it's kinda hard to search for this type of question though... if you find a duplicate, please do link and I'll close... thanks. — JRG-Developer, Dec 29 '12 at 01:33
Yeah, it looks like it has been asked before... sorry, didn't find it until now! ;-P — JRG-Developer, Dec 29 '12 at 01:40
That's funny, @Carl Norum, you answered this in said previous question! Great answer by the way! — JRG-Developer, Dec 29 '12 at 01:45
I guess that explains why I thought I'd seen it before... =) — Carl Norum, Dec 29 '12 at 01:45

score 7 · Accepted Answer · answered Dec 29 '12 at 01:31

7

The two are exactly the same. They both are equally safe.

This feature is inherited from C, where comparing to zero is implicit.

answered Dec 29 '12 at 01:31

1 Answers1