Question

So the standard rule is if an object is created with alloc, copy or retained, it needs a subsequent release. Objects created with convenience methods are autoreleased.
But what about temp vars defined with “=” and used in the scope of a method? eg

NSError *error = nil;
NSString *tempString = @"foo";
int number = otherInt * 32;
NSUInteger row = [indexPath row];
NSArray *sameArrayDifferentPointer = otherArray;

or even

NSArray *sameArrayDifferentPointer = (*NSMutableArray) otherMutableArray;

I know the last one is ‘bad’ but compiles fine and doesn’t throw exceptions.

Answer 1

error, number and row aren’t objects (or pointers to objects) so they don’t need to be (and indeed can’t be) released. (number is an int, row is either an unsigned int or an unsigned long, error is a pointer to nil.)

tempString will be autoreleased—the line

NSString *tempString = @"foo";

is the equivalent of

NSString *tempString = [NSString stringWithString:@"foo"];

Writing it the second way makes it clearer what’s going on. Likewise, your arrays are the equivalent of calling [NSArray arrayWithArray:otherArray].