This is entirely incorrect.

nil is a pointer to the value 0, and in C there is only one value that evaluates to a logical false, which is 0. Invoking a method on nil returns 0. This itself alleviates the kind of nil-check-chains discussed in this thread:

    [[[user profile] name] isEqualToString:@"Paul"];

    [user profile] && [[user profile] name] && [[[user profile] name] isKindOf:NSString] && [[[user profile] name] isEqualToString:@"Paul"];

if user.profile.name is nil, then that expression evaluates to the value 0, which as we discovered, is the _only value that evaluates to false in C_