Dynamicaly Typed(动态定型), Objective-C Runtime Programming
DynamicalyTyped(动态定型),Objective-CRuntimeProgrammingObjective-C跟C最大的差别,应该是动态定型(dynamicalytyped),支持在运行时动态类型决议(dynamictyping),动态绑定(dynamicbinding)以及动态装载(dynamicloading)。Objective-C在运行时可以允许根据字符串名字来访问方法和类,