Question

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSData *data = nil;
data = [prefs dataForKey:[NSString stringWithFormat:KEY_STR, index]];

the NSData actually has 1.5M size, can I release the memory, as soon as I done with data?

Answer 1

You’d need to create your own NSAutoreleasePool for this operation:

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
// Your code here
[pool drain];

But unless you have a good reason to, you should know that as soon as you’re done handling the event you’re handling and the app returns back to the main run loop, the default autorelease pool will drain and your memory will be released. So I wouldn’t worry about it unless you think there’s a good reason to.