iOS- Memory Management

1. alloc, new, when the copy an object, the object's reference count is 1

　　Reference count is 0, to release

2. retain +1

　release -1

　retainCount inaccurate

3. When the object reference count is 0 need to be destroyed, the system will call - (void) dealloc method must call [super dealloc] code and write back all

4. ARC (Automatic Reference Counting) automatic reference count

　　The compiler will automatically add the retain / release methods in place

　MRC (Manul Reference Counting) reference count manually

5. Close ARC

6. zombie objects: the object is released

　　Wild pointers: pointing to an object pointer zombie

　　Enable zoobie objects

　7. Global breakpoints

 8. NSLog(@"%s", __func__)

9. The message sent to the null pointer is no response, the no error.

10. - （void)setPerson:(Person*)person{

　　if(_person != person){

　　　　[_person release];

　　　　_person = [person retain];

}}

　　- (void)dealloc{

　　Object Properties release;

　　[super dealloc];

}

11. @property(nonatomic, retain/assign) Person person;

　　retain: automatically generate the code setter memory management

　　assign: produces normal setter / getter code is not written, then assign default