Starting from 0, we use the real-world examples to get started with our abstract object-oriented programming ideas. A large number of examples explain the abstract concepts clearly through the examples around us.
Object-oriented programming languages must have language components that describe objects and their relationships. These programming languages can be summarized into the following categories: everything in the system is an object; objects are encapsulations of attributes and their operations; objects can be divided into classes according to their properties, and objects become instances of classes; instance relationships and inheritance relationships are Static relationship between objects; message passing is the only form of dynamic connection between objects and the only form of calculation; the method is the sequence of messages. In object-oriented programming (English: Object-oriented programming, abbreviation: OOP), an object is a whole composed of information and a description of the processing of information. It is an abstraction of the real world.