CODEWITHSUNDEEP
objective-cmemory-management
giorgiga
giorgiga

Reputation: 1778

Does "self.propery = [[SomeClass alloc] init];" leak memory?

Is it safe in Objective-C to write

self.propery = [[SomeClass alloc] init];

instead of

SomeClass *tmp = [[SomeClass alloc] init];
self.property = tmp;
[tmp release];

or will the first form leak memory?

Upvotes: 0

Views: 923

Answers (4)

Jerry Jones
Jerry Jones

Reputation: 5403

It doesn't make a bit of difference whether or not your property is defined as retain, copy, or assign. When you create a local instance of a class with [[SomeClass alloc] init], you are responsible for releasing it within the scope it was created.

Kevin's response is correct. If you do not feel like creating, setting, releasing - you can use autorelease. The main autorelease pool is drained from time to time, you will not be using that memory for the lifetime of the application.

It is worth noting that the unpredictable nature of autorelease pools means that you can not be sure when that memory will be released. If working in a memory constrained platform like the iPhone, you should avoid using autorelease except in places where necessary.

Upvotes: 0

Kevin Sylvestre
Kevin Sylvestre

Reputation: 38012

The first example leaks unless you provide a custom property setter. You can use:

self.propery = [[[SomeClass alloc] init] autorelease];

Instead.

Upvotes: 5

Stephen Darlington
Stephen Darlington

Reputation: 52565

It depends on how the property is defined. If it's defined with retain or copy then, yes, your first example will leak.

Upvotes: 2

gcamp
gcamp

Reputation: 14662

The first one will leak.

You must release or autorelease anything you [[ alloc] init] when you don't need it anymore.

Refer to this guide.

Upvotes: 0

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