Introduction to Software Engineering: The core content of the second chapter

 1. Software Engineering Methodology: A set of techniques used throughout the whole process of the life cycle of a program becomes a methodology, also known as a paradigm. Three elements: methods, tools, processes   2. The traditional method features: the traditional methodology divides the whole process of software life cycle into several stages, then sequentially completes each stage's task. The beginning and end of each phase have strict standards, and for any two adjacent phases the end criterion of the previous phase is the starting standard for the latter phase. (2) The characteristics of object-oriented approach: object-oriented approach is the method of combining data with the operation of data, its starting point and the basic principle is to imitate the way of thinking of human habits as far as possible, so that the development of software methods and processes as close to human understanding and problem solving methods and processes, applicable to large, Complex and highly interactive systems   3. Formal methodology: It is a software development method based on formal mathematical transformation, which can transform the system specification into an executable program. Features: The software Requirements specification is refined into a detailed formal specification with mathematical notation; the development process, such as design, implementation, and unit testing, is replaced by a transformation development process, which refines the formalized specification into a program through a series of transformations. Object-oriented = object + class + inheritance + message communication, the basic component of object-oriented program is the class, the core is the object.   Object-oriented development methods: Booch method, Rumbaugh method, Coad and Yourdon method, Jacobson (Osse) method, Wirfs-brock method   4. Class. Objects in real life are abstracted and mapped to objects in a program. An object is described in a program as an abstract data type, which is called a class.    encapsulation. Object-oriented encapsulation features are closely related to their abstract characteristics. Encapsulation is an information masking technique that encapsulates data and data-based operations with abstract data types. The user can only see the object's encapsulated interface information, and the object's internal details are hidden from the user. The definition of    encapsulation is: (1) Clear boundary, the internal information of all objects is confined within this boundary, (2) interface, i.e. the method that the object provides to the outside world, the outside world can interact with the object through these methods, and (3) The protected internal implementation, that is, the implementation details of the Software object function, Implementation details cannot be accessed from outside the class.   5.  features of UML: A. Uniform standards. B. Object-oriented. C. Visualization, strong expression ability. D. independent of process. E. Easy to master use. F. Relationship with programming languages   6. Software tools are used to support the needs of a certain stage of the software's life cycle, such as system definition, requirements analysis, design, coding, testing, or maintenance, etc.Software tools. Development of   software tools: Programming languages emerged in the late 50, the concept of software engineering was put forward in the late 60, new concepts of the process were put forward in the mid-80, and today, software tools focus on the design of user interfaces and constantly adopt new theories and technologies.

Introduction to Software Engineering Chapter II core content