PREFACE Object-Oriented Programming Concepts Class Object State Behavior Constructors Abstraction Encapsulation and Data Hiding Interface Implementations Inheritance Polymorphism Overloading Overriding Relationships among Classes Association Aggregation Composition Creating and Reusing classes Loose coupling High cohesion Advantages of object-oriented programming UML Diagrams for developers Why do we model? UML Class Notation Relationships among classes Association Aggregation Composition Dependency Inheritance (or Generalization) Realization The implemented code reflects the intent of the UML designer Why do we model with UML? Coding Practices Clean code has Intention-Revealing names Clean Code tells a story Functions should do one thing Don’t comment on bad code; rewrite it Comment on what is necessary SOLID PRINCIPLES Single Responsibility Principle (SRP) The Problem: A Class has more than one responsibility The solution: Create Classes with only one responsibility Open-closed Principle (OCP) When we cannot visualize future requirements When suddenly, an unexpected scenario arises Enabling the Open-Closed Principle Liskov Substitution Principle (LSP) Describe an Object with the minimal behavior required When the minimal behavior required is broken Interface Segregation Principle (ISP) When a Class includes no-related functionalities Enabling the Interface Segregation Principle Dependency Inversion Principle (DIP) Changes made to dependent code are always risky. Dependency Inversion removes tight dependency between classes Apache Log4j Vulnerability When Clients target to an interface B2B Integration Project Duplicated effort The requirement Your creative process in action Know what you are trying to achieve The company policies influence your design Read and understand the requirements documentation. Divide and Conquer DRY (Don’t Repeat Yourself) Communicating software design decisions Visualizing software architecture Context diagram Container diagram Component diagram Code diagram How the new design handle complexity better