Question

//.h file
@property(nonatomic, retain) NSMutableDictionary *data;

//.m file
NSMutableDictionary *temp = [[NSMutableDictionary alloc] init];
self.data = temp;
[temp release];

Why is this way (using temporary variable) is better than this

self.data = [[NSMutableDictionary alloc] init];

What is the difference?

Answer 1

The second way leaks the newly-created dictionary. You could use:

self.data = [NSMutableDictionary dictionary];

And it would be as safe as your first example.

Edited to match OP’s update to the question.