solid-principles

I am trying to learn the Single Responsibility Principle (SRP) but it is being quite difficult as I am having a huge difficult to figure out when and what I should remove from one class and where I should put/organize it. I was googling around for some materials and code examples, but most materials I found, instead of making it easier to understand, made it hard to understand. For example if I have a list of Users and from that List I have a class Called Control that does lots of things like Send a greeting and goodbye message when a user comes in/out, verify weather the user should be able

I have an existing bank application classes as shown below. The banks account can be of SavingsBankAccount or FixedBankAccount. There is an operation called IssueLumpSumInterest. For FixedBankAccount, the balance need to be updated only if the owner of the account has no other account. This demands the FixedBankAccount object to know about other accounts of the account owner. How to do this by following SOLID /DDD/GRASP/Information Expert pattern? namespace ApplicationServiceForBank { public class BankAccountService { RepositoryLayer.IRepository<RepositoryLayer.BankAccount> accountRepository;

Recently I heard that there are 9 rules for OOP(Java). I know only four as Abstraction, Polymorphism, Inheritance and Encapsulation. Are there any more rules for OOP? Seems like what you're looking for are the Principles of Object-Oriented Design . Summarized from Agile Software Development Principles, Patterns, and Practices . These principles are the hard-won product of decades of experience in software engineering. They are not the product of a single mind, but they represent the integration and writings of a large number of software developers and researchers. Although they are presented

Can someone give me an example of the Single Responsibility Principle? I am trying to understand what it means, in practice, for a class to have a single responsibility as I fear I probably break this rule daily. Check out the Solid description . Unless you ask for something more specific, it will be hard to help more. Single responsibility is the concept of a Class doing one specific thing (responsibility) and not trying to do more than it should, which is also referred to as High Cohesion. Classes dont often start out with Low Cohesion, but typically after several releases and different

Can you explain Liskov Substitution Principle (The 'L' of SOLID) with a good C# example covering all aspects of the principle in a simplified way? If it is really possible. jgauffin (This answer has been rewritten 2013-05-13, read the discussion in the bottom of the comments) LSP is about following the contract of the base class. You can for instance not throw new exceptions in the sub classes as the one using the base class would not expect that. Same goes for if the base class throws ArgumentNullException if an argument is missing and the sub class allows the argument to be null, also a LSP

What is the dependency inversion principle and why is it important? Carl Seleborg Check this document out: The Dependency Inversion Principle . It basically says: High level modules should not depend upon low-level modules. Both should depend upon abstractions. Abstractions should never depend upon details. Details should depend upon abstractions. As to why it is important, in short: changes are risky, and by depending on a concept instead of on an implementation, you reduce the need for change at call sites. Effectively, the DIP reduces coupling between different pieces of code. The idea is