Kalou

摘要： object composition (Decorator pattern) is often a better technique than subclassing for extending class behavior.1.Abstract Factoryprovides an interface for creating families of related or dependent objects without specifying their concrete classes提供接口创建相同或类似的对象，不需要指定其具体的类型iso中主要体现在NSNumber和NSArray和 阅读全文