内存管理和特性

//  RetainTrackCategory.m//  MemoryManager////  Created by 110 on 10-1-26.//  Copyright 2010 __MyCompanyName__. All rights reserved.//#import "RetainTrackCategory.h"/** 类别：是一种为现有的类添加新方法的方式。 只有保证类别名称的唯一性，你可以向一个类添加任意多的类别  */@implementation RetainTrackCategory (RetainTrackCategory) -(NSString *) print{NSLog(@"pring-------");}@end