In dealloc method set any delegate to nil is needed or not needed

I have created tableview in my view by programmatic like below

table = [[UI开发者_开发百科TableView alloc] initWithFrame:CGRectMake(0, 44, 320, 370) style:UITableViewCellStyleDefault];
table.delegate = self;
table.dataSource = self;
table.separatorStyle = UITableViewCellSeparatorStyleNone;
[self.view addSubview:table]; 

in dealloc method i write like below

table.delegate = nil;
 table.dataSource = nil;
[table release];
table=nil;

this the better way or below one is better

[table release];
table=nil;

I want to know if i dont reset delegate and dataSource what will happen

Thanq

If you are deallocating an object that acts as the delegate to other objects, you need to make sure that you have set their delegates to nil, before you call [super dealloc] (assuming the normal pattern that objects do not retain their delegates). This is because when [super dealloc] has returned, this object is no longer a valid object and the objects it is a delegate to effectively have dangling references, if they have not been set to nil.

In this particular case, you would probably get away without doing it because your object's dealloc probably won't get called except when the UI is being dismantled and the table view no longer needs to use its delegate or data source, but don't bet on it.

From Setting delegate to nil in dealloc:

It's a defensive programming move. It's clearing out the reference to the delegate object incase something else in your object tries to access the delegate after you've told it that you're done with it. As part of your dealloc you might have a method or do something that triggers a KVO notification that makes a call to the delegate. So setting the delegate's reference to nil prevents that from happening. If it did happen you could end up with some oddball crashes that are fun to reproduce and fix.

To add to the answers above, you do not need

table = nil;

in your dealloc. It won't hurt, but it is not necessary to nil out your ivars. Your view is being dealloc'ed and therefore your ivars will no longer be accessible. You are probably confusing that with:

self.table = nil;

which can function as an alternative way to release if you are accessing the ivar via a property.

Of course if you have ARC turned on, then you don't need the release at all.

And to answer your actual question, if you don't nil out the table's delegate and datasource on the dealloc of the view....nothing will happen. They are set to the view, which is in the process of being released. In this case, you will have no issues not doing it. In theory it's good form.