Introduction to Four Principles Of Simple Design


Image


CHECK OUT OUR 8 AMAZING AWS CERTIFICATION COURSES HERE


With agile and extreme programming, the focus is on keeping your design simple. How do you keep your design simple? How do you decide whether your code is good enough?

Free Courses - Learn in 10 Steps

Software Design Principles

This is the first article in a series of articles on important Software Design Principles:

What is Simple Design?

It is very important to keep the design of your application simple.

In almost all agile projects, the aim is to meet today’s requirements, with clean code.

You go for complex design, only when simple design does not solve your problem.

The Four Principles Of Simple Design

A software application is said to have a simple design if it:

  • Runs all tests
  • Contains no duplication
  • Expresses intent of programmers
  • Minimizes number of classes and methods

Let’s now look at these aspects a little closely, by turn.

Runs All Tests

We want to keep running all the tests continuously, because we want the code to work, at all times.

An important corollary of this principle is you need to have a large number of automation tests. All unit, integration and API tests must be automated.

You should launch these tests as part of your build, and they should also be a part of Continuous Integration (CI).

With CI, you commit code into the repository, all the tests are run, and immediate feedback is there for you to act on.

Since the software is being tested all the time, it is stable.

Contains No Duplication

The second principle stresses on the fact that your code should have as little duplication as possible.

A good example is to create common components, whereever possible, in the design of large applications. This helps centralize the logic and allow other applications to reuse them.

Why do we hate duplication?

If there is a need for a change, the same change needs to repeated at all these locations. The result : More effort and also possibilities of more defects when you miss making the change in every location. That is a sign of bad design.

Expresses Intent Of Programmers

Your code should be easy to read, and your design, simple to understand. This principle is also called Clarity Of Code.

Have a look at the following piece of code:

Example-01 v1

image info

Do you understand what it does?

Now look at the following version of the same program:

Example-01 v2

image info

Do you understand what it’s trying to do?

Actually, Example-01 v2 results from applying the Four Principles of Simple Design to Example-01 v1.

Start with creating good names for variables, methods and classes. That improves clarity.

Minimize number of classes and methods

You should have

  • Small methods
  • Small classes
  • Minimum number classes and methods

Isn’t it simple.

Lesser code you have, lesser code you have to maintain.

Always aim to keep things simple.

Do check out our video on this:

image info

Summary

In this article, we looked at the four principles of simple design. These are the first steps to ensure that the design of your application remains simple. It lays the foundation for applying more advanced principles to improving your design.

8 AWS Certification Courses

We are releasing courses for 3 Certifications under 3 categories - STEP BY STEP, EXAM REVIEW and PRACTICE TESTS:

  • Step by Step courses are for you if you are getting started with AWS
  • Exam Review courses help you to quickly review for the exam in a few hours
  • Practice Tests help you to test your preparation - How ready are you for the exam?

STEP BY STEP COURSES: ZERO AWS KNOWLEDGE? Start your journey now!

EXAM REVIEW COURSES: You prepare for the exam for 1-6 months. How do you remember everything you studied? Review for the exam in under 6 HOURS using this crash courses!

PRACTICE TESTS: Test yourselves for the certification exam with our practice tests

Best Selling Udemy Courses

Image
Image Image Image Image Image Image Image Image Image Image Image

Join 450,000 Learners and 30+ Amazing Courses

350,000 Learners are learning everyday with our Best Selling Courses : Spring Boot Microservices, Spring, Spring Boot, Web Services, Hibernate, Full Stack React, Full Stack Angular, Python, Spring Interview Guide, Java Interview, Java Functional Programming, AWS, Docker, Kubernetes, PCF, AWS Fargate and Azure


Do not know where to start your learning journey? Check out our amazing learning paths:
Learning Path 01 - Spring and Spring Boot Web Applications and API Developer,
Learning Path 02 - Full Stack Developer with Spring Boot, React & Angular,
Learning Path 03 - Cloud Microservices Developer with Docker and Kubernetes,
Learning Path 04 - Learn Cloud with Spring Boot, AWS, Azure and PCF and
Learning Path 05 - Learn AWS with Microservices, Docker and Kubernetes


Subscribe

FREE COURSES



Related Posts

Understanding jwt token

Let us understand the json web tokens

Single sign-on workflow

Let us understand the single sign-on workflow

Oauth2.0 - Resource Owner Password Credentials grant workflow

Let us understand the Oauth2.0 Resource Owner Password Credentials grant workflow

Oauth2.0 - Implicit grant workflow

Let us understand the Oauth2.0 implicit grant workflow

Oauth2.0 - Client Credentials grant workflow

Let us understand the Oauth2.0 client credentials grant workflow

Oauth2.0 - Authorization grant workflow

Let us understand the Oauth2.0 authorization grant workflow

Writing Integration Tests for Rest Services with Spring Boot

Setting up a basic REST Service with Spring Boot is a cake walk. We will go one step further and add great integration tests!

Integrating Spring Boot and Spring JDBC with H2 and Starter JDBC

Learn using Spring Boot Starter JDBC to connect Spring Boot to H2 (in memory database) using Spring JDBC. You will create a simple project with Spring Boot. You will add code to the project to connect to a database using Spring JDBC. You will learn to implement the basic CRUD methods.

JUnit Tutorial for Beginners in 5 Steps

JUnit Tutorial for Beginners in 5 Steps. Setting up a basic JUnit example and understanding the basics of junit.

JPA and Hibernate Tutorial For Beginners - 10 Steps with Spring Boot and H2

JPA and Hibernate in 10 Steps with H2 - Setting up a basic project example with Spring Boot and in memory database H2. Its a cake walk.


Search