Is garbage collection supported for iPhone applications?

Question

Does the iPhone support garbage collection? If it does, then what are the alternate ways to perform the operations that are performaed using +alloc and -init combination:

NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithData:xmlData];
UIImage *originalImage = [[UIImage alloc] initWithData:data];
detailViewController = [[[DetailViewController alloc] initWithNibName:@"DetailView bundle:[NSBundle mainBundle]] autorelease];

... and other commands. Thank you in advance for any help or direction that you can provide.

Answer 1

No, garbage collection is not supported on the iPhone currently. You need to use alloc/release/aurorelease.

Answer 2

No. Garbage collection is too large an overhead for the limited battery life etc. on the device.

You must program always with an alloc/release pattern in mind.

NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithData:xmlData];
...
[xmlParser release];

or (not suitable for every situation)

NSXMLParser *xmlParser [[[NSXMLParser alloc] initWithData:xmlData] autorelease];

Hope this helps!

Answer 3

Thanks for the help. Just realised that i did saw the answer some where, and now i know where:

Creating iPhone Application - No Garbage Collection feature

silly me : )

Answer 4

Note the lack of garbage collection means weak references are not supported either.

Answer 5

”No. Garbage collection is too large an overhead for the limited battery life etc. on the device.”

I disagree. If this is true then how come GC is implemented in Java Micro Edition which targets wireless devices?

Answer 6

Mono touch has garbage collection and runs on the iPhone os.

Answer 7

In the entire discussion nobody says about the Java language, in Java the Garbage collection is in-built in the language so it is implicitly available in Android,J2ME and Blackberry :), where as in Objective-C it is optional, so in iPhone the GC is not available.