tailieunhanh - Lecture Software design and architecture – Chapter 18

Lecture 18 – Object orientation. An object is an entity with a well-defined boundary and identity that encapsulates state and behavior. State is represented by attributes and relationships; behavior is represented by operations, methods, and state machines. | SOFTWARE DESIGN AND ARCHITECTURE LECTURE 18 Review User interface Design principles Design Guidelines Outline Basic Concepts of Object Oriented. Modeling UML and OO Modeling Basic Concepts of Object Orientation Object Class Message Basic Principles of Object Orientation Abstraction Encapsulation Inheritance Polymorphism Interface and Abstract Class Informally, an object represents an entity, either physical, conceptual, or software. Physical entity Conceptual entity Software entity What Is an Object? Chemical Process Linked List Objects allow the software developer to represent real-world concepts in their software design. These real-world concepts can represent a physical entity such as a person, truck, or space shuttle. Objects can be concepts like a chemical process or algorithms. Object can even represent software entities like a linked list. A More Formal Definition An object is an entity with a well-defined boundary and identity that encapsulates state and behavior. State is | SOFTWARE DESIGN AND ARCHITECTURE LECTURE 18 Review User interface Design principles Design Guidelines Outline Basic Concepts of Object Oriented. Modeling UML and OO Modeling Basic Concepts of Object Orientation Object Class Message Basic Principles of Object Orientation Abstraction Encapsulation Inheritance Polymorphism Interface and Abstract Class Informally, an object represents an entity, either physical, conceptual, or software. Physical entity Conceptual entity Software entity What Is an Object? Chemical Process Linked List Objects allow the software developer to represent real-world concepts in their software design. These real-world concepts can represent a physical entity such as a person, truck, or space shuttle. Objects can be concepts like a chemical process or algorithms. Object can even represent software entities like a linked list. A More Formal Definition An object is an entity with a well-defined boundary and identity that encapsulates state and behavior. State is represented by attributes and relationships. Behavior is represented by operations, methods, and state machines. An object is an entity that has a well-defined boundary. That is, the purpose of the object should be clear. An object has two key components: attributes and operations. Attributes represent an object’s state, and operations represent the behavior of the object. Object behavior and state are discussed in the next few slides. Take a moment to explain the graphic on this slide. Attributes are documented on the inside of the doughnut. Operations are documented on the borders, which will become clear to the student as we discuss topics like encapsulation. Note that the doughnut is not part of the UML notation. UML notation will be discussed later. An Object Has State The state of an object is one of the possible conditions in which an object may exist. The state of an object normally changes over time. The state of an object is one of the possible conditions that an object may