What is a class? What is an object? What is the relationship between them?

A class is the definition of an object, and an object is an instance of a class.

Answer: An object is an abstract entity that contains the features of a real-world object and reflects the system's ability to hold information and interact with it. Each object has its own internal properties and operation methods, and the whole program is composed of a series of interacting objects, and the interaction between objects is achieved by sending a pre-band message.

A class is a collection of objects that have the same properties and methods of operation, and follow the same rules. Externally, the behavior of a class can be specified with newly defined actions (methods).

A class is an abstraction of a collection of objects that dictates the common properties and methods of those objects; An object is an instance of a class.

The concept of a class: A class is a group of objects with the same properties and services

Provides a unified abstract description for all objects belonging to the class, which consists of two main parts: properties and services.

In object-oriented programming languages, a class is a separate unit of program that should have a class name and include two main parts: the description of the property and the description of the service.

The concept of dialogue and imagery: an object is an entity used in a system to describe objective things, and it is a basic unit that constitutes a system.

An object consists of a set of properties and a set of services that operate on that set of properties.

From a more abstract point of view, an object is an abstraction of something in the problem domain or implementation domain, which reflects the information that needs to be stored and the role that the thing needs to play in the system; It is an encapsulation of a set of properties and a set of services that have the authority to operate on those properties.

The objective world is made up of disturbing objects and the connections between them.

The relationship between a class and an object is like that of a molded lifter and a casting, the result of the instantiation of a class is an object, and the abstraction of a class of objects is a class.

A class describes a set of objects that have the same properties (properties) and the same behavior (methods).

The relationship between a class and an object is that a class is an abstraction of an object, and an object is a concrete instance of a class.

Classes are abstract and do not occupy memory, while objects are concrete and occupy storage space. A class is a blueprint used to create an object, and it is a software template that defines the methods and variables included in a particular type of object.

The relationship between a class and an object is like the relationship between a mold and a casting, where the result of an instantiation class is an object, and an abstraction of a class of objects is a class, which describes a set of objects with the same properties and the same methods. Chagao.