Possible Duplicate:
Double parentheses in sample code
Often the init method in an Objective-C class will have the following line:
if ((self = [super init])) { ...
I'm just wondering if the extra parentheses are necessary. Is the following line equivalent?
if (self = [super init]) { ...
Edit: This is indeed a duplicate of Double parentheses in sample code
They are not necessary, but using (( and )) say "yes, I mean an assignment, not a comparison."
In fact clang will warn you about using assignment in an if condition and suggest double parentheses for unambiguity.
In general I think this could be considered bad coding style, but an exception is made here since this is a special frequently used pattern in obj-c
