Object-oriented analysis and design read Note two

Today, I read the second chapter object model of object-oriented analysis and design, from the first generation of computer to the evolution of object-oriented programming, has undergone a long evolution, while object-oriented programming is also a historical evolution. So what is object-oriented programming? Object-oriented programming is actually a method of implementation, in which the program consists of a number of collaborative objects, each representing an instance, and the class belonging to a hierarchy formed through an inheritance relationship. I used to think that object-oriented programming is not about writing a class, and then using a class to create an object that uses objects to implement some of these functions. Now it seems that the idea is a bit partial.

Each programming style is based on its own conceptual framework. For all object-oriented things, the conceptual framework is the object model, which has 4 elements (1) abstraction (2) Encapsulation (3) modular (4) hierarchy. Abstract describes the basic characteristics of an object, which can be distinguished from all other types of objects; encapsulation is a process that is separated into an abstract structure and behavior element; a hierarchy is a hierarchical or sort of abstraction. The maturity of software engineering leads to the formation of object-oriented analysis, design and programming methods, which solves the problem of large-scale programming, which solves the complexity of software. The habit of previous programming is to write functions of several functions into the main function, called in the main function, so that later the code is more complex, and even can not find their own code. Then slowly found that the programming method is not correct, the use of object-oriented programming ideas, the program will be much easier. and easy to maintain and manage.

Object-oriented analysis and design read Note two