OBJECTIVE-C----Autorelease Pool

Autorelease Pool Usage Precautions:

1. Under ARC, you cannot use [[NSAutoreleasePool alloc] init], but you should use @autoreleasepool;
2. Do not put a large number of cyclic operations between the same nsautoreleasepool, which will cause memory spikes in the rise;
3. Try to avoid using this method for large memory, or use it sparingly for this delayed release mechanism;
4. The objects created and returned by the general static method in the SDK are autorelease and do not require release operations; for example: [NSNumber numberwithint:10]; The returned object does not need to be re-release, but the object created by [[NSNumber Alloc] initwithint:10] needs to be release;
5. Any variable defined in curly braces cannot be used outside of parentheses. This is the typical C language of the effective range, such as loop code.

OBJECTIVE-C----Autorelease Pool