concrete base class的意思|示意

Another helpful addition to PHP V5 is the abstract class, which makes it easy to have one base class to implement the core of an interface from which you then create concrete classes.

PHP V 5中另一个有帮助的新功能是抽象类，使用抽象类可以轻松地用一个基类实现接口的核心部分，然后用该接口创建实体类。

Concrete classes provide the appropriate implementation for their respective base class. The Factory Method Pattern consists of the following classes.

concrete类为它们各自的基类提供恰当的实现。

Thus, the class that knows the algorithm is not an abstract base class, but a concrete class that uses a helper that implements an interface defining the individual steps.

因此，了解算法的类不是一个抽象类，而是一个定义了具体的操作步骤，用帮助类实现了接口的具体的类。

In a base class, abstract class is defined by declaring pure virtual function, a derived class must define all inherited pure virtual functions of its base classes to be concrete.

在基类中可以通过将虚函数声明为纯虚函数的手段来定义抽象类，强制派生类在自己的类定义中实现虚函数的具体功能。