编程实现类的定义，掌握C++面向对象基本特性，如抽象、继承、重载、多态，理解虚函数、构造函数、析构、模板等基本概念与基本语法-Realize the definition of types of programming, master C++ Basic object-oriented features such as abstraction, inheritance, overloading, polymorphism, understanding virtual function, cons