Also, this question is much more appropriate for the objc-language list than it is for cocoa-dev.
--Kyle Sluder On Fri, Feb 24, 2012 at 6:50 AM, Oleg Krupnov <oleg.krup...@gmail.com> wrote: > An interesting question. The following samples are equivalent in terms > of compiled code, but which one is more correct from the language's > point of view? > > self = [super init]; > if (self) > { > } > return self; > > self = [super init]; > if (self != nil) > { > } > return self; > > The Xcode samples promote the first variant, but I'm wondering if the > second one is more correct? > > The "nil" is defined as follows (jumped to definition) > > #define nil NULL > #define NULL ((void*)0) > > So basically, nil is of type "void*", so the expression "self != nil" > compares two pointers and the result is "boolean", which is perfect > for testing in the "if" statement. But the "self" alone is of type > "pointer" and so when it is tested by the "if" statement, it's > implicitly cast to the type "boolean". > > I also heard that generally speaking NULL is not necessarily always > equal to 0 on all architectures. > > Thoughts? _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com