sas base

(1) Access to base class membersAccess the members of the base class through the base keyword:Calls a method on the base class that has been overridden by another method.Specifies the base class constructor that should be called when creating an instance of a derived class.B

C + + notes: Derived classes to base class conversions to accessibility to determine whether a conversion to a base class is accessible, you can consider whether the public member of the base class is accessible and, if so, that the conversion is inaccessible, otherwise it can be accessed. If it is public inheritance, both user code and descendant classes can

Where to use the virtual base class:Why avoid ambiguity caused by multiple public base classes in multi-layer inheritanceVirtual base class UsageWhen a derived class inherits a base class, the virtual base class is inherited by the addition of an Vsan keyword.In the program

/** This keyword* This keyword references the current instance of the class* Note: The This keyword cannot be used in static member methods, and the This keyword can only be used in instance constructors, instance methods, or instance accessors*//** Base keyword* The base keyword is used to access the members of the base class from the derived class;* Specifies t

Only a public derived class is a true subtype of the base class, and it inherits the functionality of the base class completely. There is an assignment-compatible relationship between the base class and the derived class object, because the derived class contains members that inherit from the base class, so the value o

C + + clearly states: when the derived class object is deleted by a base class pointer, and the base class takes a non-virtual destructor, the result is undefined-- The actual execution usually occurs when the derived component of the object is not destroyed! (Note: Using polymorphism in the way that a base class references a derived class, because a reference is

Review the knowledge of C + + today, when see the virtual base class this time, there is no too much to investigate, is to know that the virtual base class is to eliminate the class inheritance between the two semantic problem, but is very curious, how it is eliminated, how the memory layout is distributed? So I studied it in depth, and the concrete principle is as follows: In C + +, obj is a class object,

After learning, has a general understanding of the development process of the Android program, in order to improve our interest in learning, in this section we will write a simple base station locator program. Now lbs (Location Based service, location-based services) mobile applications are quite popular (such as: micro-letters, customers, muttering, street, etc.), base station positioning is one of the key

inheritance:Class Derived classes: Virtual base class 1,virtual base class 2, Virtual base class 3 ...{};Constructor procedure:The constructor of the virtual base class is executed first, and the constructors of many virtual base classes are constructed in the order of inhe

The derived class inherits the base class. During memory allocation, it is located in different memory addresses of the base class object. Based on the member variable type of the base class, a space of the same type is opened, but note that the space of the derived object after the development is opened, instead of copying the value of the

During polymorphism, it is best to set the destructor of the base class to virtual. In this way, the destructor of the subclass will be called first, and then the destructor of the base class will be called, otherwise, if Delete is a pointer to the base class, only the destructor of the base class will be called. examp

Multiple inheritance of implicit classes describes classes with multiple direct base classes. Multi-inheritance brings two main problems: ① Inherit the same name method from two different base classes; ② Inherit multiple instances of the same class from two or more related base classes. For example: Class { PRIVATE: String name; Int ID; Public: Virtual void F ();