Software Design

Understanding the Problem Imagine you’re building a text editor. Users often make mistakes or want to revert changes. How can you allow them to undo their actions without exposing the internal state of the document? The Memento Solution The Memento pattern provides a solution by capturing and storing the internal state of an object without violating encapsulation. Key Players: Originator: The object whose state needs to be saved (e.g., the text editor)....

The Mediator pattern promotes loose coupling between objects by introducing a mediator that handles communication between them. This reduces dependencies and makes the system more flexible and maintainable. A Simple Chat Room Example Let’s consider a basic chat room application with multiple users. Instead of users communicating directly with each other, they’ll send messages to a chat room (the mediator), which then broadcasts the message to all users. 1. Define the Mediator Interface: interface ChatRoom { void registerUser(User user); void send(String msg, User user); } 2....

What is a Use Case Diagram? A use case diagram is a type of drawing that shows how different people (called “actors”) interact with a system (like a software program or website). It’s a way to show what the system does and who uses it. Key Notions (Symbols) in a Use Case Diagram: Actors: Stick Figure: Represents a person or thing that interacts with the system. For example, a student, teacher, or librarian....

Unified Modelling Language (UML) is a standardised way to visualize the design of a system. UML diagrams can be categorized into two main types: Structural Diagrams and Behavioral Diagrams. Understanding these categories helps in effectively modeling both the static and dynamic aspects of a system. Structural Diagrams Structural diagrams represent the static aspects of a system. They show the system’s classes, objects, and relationships. Here are the key types of structural diagrams:...

In the journey of software development, visual aids like diagrams play a crucial role. They help in understanding, designing, documenting, and communicating different aspects of a system among team members and stakeholders. Let’s dive into some of the most commonly used diagrams in software development. 1. Unified Modeling Language (UML) Diagrams Unified Modeling Language (UML) is a standard language which is not about coding but about visualizing. It helps to model software, systems, and business processes....

Introduction: The SOLID principles are a cornerstone for designing robust, maintainable, and scalable systems. These principles, introduced by Robert C. Martin, provide a foundation for good software design. In this article, we’ll break down each principle with examples, making it easy for beginners to grasp these essential concepts. 1. Single Responsibility Principle (SRP): The Single Responsibility Principle states that a class should have only one reason to change, meaning it should have only one job....