Gang Of Four: In 1994, four authors Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides published a book titled Design Patterns — Elements of Reusable Object-Oriented Software which initiated the concept of Design Pattern in Software development.

Design patterns are divided into 3 main categories:

1. Creational: Creational patterns deal with the creation of objects.
2. Structural: Structural patterns deal with class structure such as Inheritance and composition.
3. Behavioral: Behavioral patterns provide solution for the better interaction between objects. How to provide loose coupling & flexibility to extend easily in future.

In this blog, we will proceed with Singleton pattern which is a type of Creational design patterns.

Singleton Design Pattern

This pattern is used when we need only one instance of a class. All furthur references to the objects are referred to the same underlying instance created.

Implementation:

• Declare all constructors as private.
• Provide static method that returns an instance of class.
• The instance is stored as a private static variable.

public static sealed class Singleton
{
  private static Singleton instance = null; // private static variable.

  private Singleton()
  {  
    //Private Constructor
  }

  public static Singleton GetInstance // Returns instance of class.
  {
    get
    {
      if(instance == null)
        instance == new Singleton();
      return instance;
    }
  }
}

Before proceeding further, let’s discuss why should we seal the singleton class.

The Sealed keyword prevents the class to be inherited by some other class.

public static class Singleton
{
  private static Singleton instance = null; // private static variable.

  private Singleton()
  {  
    //Private Constructor
  }

  public static Singleton GetInstance // Returns instance of class.
  {
    get
    {
      if(instance == null)
        instance == new Singleton();
      return instance;
    }
  }
}

public class DerivedSingleton : Singleton 
{
  // Singleton.Singleton() is inaccessible due to it's protection level.
}

Although the private constructor will restrict the class to be inherited but if we move our class inside the singleton class, that’s where the problem starts.

public static class Singleton
{
  private static Singleton instance = null; // private static variable.

  private Singleton()
  {  
    //Private Constructor
  }

  public static Singleton GetInstance // Returns instance of class.
  {
    get
    {
      if(instance == null)
        instance == new Singleton();
      return instance;
    }
  }
  
  public class DerivedSingleton : Singleton 
  {
    // If we create an instance of DerivedSingleton, another instance of
    // singleton class will be created.
  }
}

Thus, we have to provide the sealed keyword, to restrict the class to be inherited to follow the singleton design pattern.

Conclusion: The singleton pattern is a great choice based on our use case but should be used moderatly and should not be overused. The instance created here will not be destroyed for as long as the application keeps running. This can be a little problematic if we have a large application with several such instances created, and so our memory is filling up with such instances which we don’t necessarily need all the time.

Thanks, hope it helps. Do checkout my other C# blogs.

Interfaces in C#

Level Up Coding

Thanks for being a part of our community! Before you go:

• 👏 Clap for the story and follow the author 👉
• 📰 View more content in the Level Up Coding publication
• 💰 Free coding interview course ⇒ View Course
• 🔔 Follow us: Twitter | LinkedIn | Newsletter

🚀👉 Join the Level Up talent collective and find an amazing job

Design Patterns: Singleton Design was originally published in Level Up Coding on Medium, where people are continuing the conversation by highlighting and responding to this story.

That’s when Steve Jobs came up with a game-changing idea and launched a campaign popularly known as ‘Think Different’, which is one of the best marketing campaigns even today.

In one of his Masterclass Jobs said, “Apple brand has clearly suffered from neglect”. He continued with how they can bring Apple back by not talking about the speed and fees, by not talking about bits and megahertz, and by not talking about how Apple is better than Windows.

And for inspiration, he turned to Nike.

“The best example of all, and one of the greatest jobs of marketing the universe has ever seen is Nike,” Jobs explained. In their ads, they don’t ever talk about their products. What does Nike do? They honor great athletes and they honor great athletics. That’s who they are, that’s what they are about.”

And, Let’s not get started about what Nike did when they lost the title sponsorship to Adidas of the 2012 London Olympics. Even after losing the title sponsorship, when the results came out, there we 9000 tweets associating Adidas with the Olympics, while there were 16,000 tweets associating Nike with it. And to conclude their genius strategy, in a survey after the Olympics, 27% of people said Adidas was the title sponsor of the Olympics, while 37% of people said that Nike was the title sponsor of the London Olympics.

You can checkout the survey here:

Case study: Branding strategies deployed at the 2012 Games in London

And what was the genius strategy of Nike? their “Find Your Greatness” campaign.

1. Nike was not allowed to showcase London of UK in their commercials, but they found a loophole and showcased the other 28 locations named as London in different parts of the world.
2. Nike was not allowed to hire athletes taking part in Olympics for it’s brand endorsement. So it hired teenagers for commercials and came out with beautiful advertisement. It literally broke the internet. They played with the emotion of inspiration to communicate their idea. Below I am attaching the link of that commercial because I feel words are not enough to describe this masterpiece.

Here’s the campaign video as words are not enough to describe this masterpiece.

Conclusion

Steve Jobs was inspired by Nike and launched the “Think Different” campaign.

Albert Einstein, Bob Dylan, Martin Luther King, Jr., Richard Branson, John Lennon (with Yoko Ono), Buckminster Fuller, Thomas Edison, Muhammad Ali, Ted Turner, Maria Callas, Mahatma Gandhi, Amelia Earhart, Alfred Hitchcock, Martha Graham, Jim Henson (with Kermit the Frog), Frank Lloyd Wright and Pablo Picasso. These are the famous personalities that were on the billboard and TV Ads. Indeed, this ad is strong and motivating, it can draw viewer’s attention from the first second and it remains unique until now.

Enjoy it:

Nike, Steve Jobs, And a Story to Remember…. was originally published in ILLUMINATION on Medium, where people are continuing the conversation by highlighting and responding to this story.

In C# an Interface is like a contract, in which every class which inherits it, must abide by all the interface rules, i.e., the class should provide implementation for all the interface methods.

A class must comply with the contract set out by the interface. A class simply says that I will provide you the implementation of all the methods, it’s a contract that must be fulfilled.

It should be noted that the class which inherits an interface can have other methods and fields too. Interfaces do not force you to only comply with the contract, you must implement them, yes, but you can add other methods and fields too. Your class will work as it does, just that it must provide an implementation of all the interface methods.

How do we declare an Interface?

• An interface is declared using the interface keyword, followed by the name of the interface. It’s a convention to put the letter “I” before the name of the interface in C#. The methods of an interface have access modifiers(public) return type and the method name.

public interface IEmployee
{
  public void Salary();
}

• We don’t provide the implementation of methods here, but in the class that inherits the interface. By using the: operator in its declaration followed by the names of the interfaces, a class can implement one or more interfaces.

public class Company : IEmployee
{
  public void Salary()
  {
    //Logic for Salary
  }
  public void Location()
  {
    //Locations Data
  }
}

• A class should provide implementation of all the methods of interface and can have other methods too.
• Interfaces don’t have constructors, as we cannot make an instance of an interface.
• We can inherit more the one interface in a class.

public class Company : IEmployee, IIntern, IPartTime
{
  public void Salary()
  {
    //Logic for Salary
  }
  public void Location()
  {
    //Locations Data
  }
}

• Interface members are by default abstract and public.
• Interfaces can contain properties and methods, but not fields/variables.

Why do we use Interface?

• To achieve security: Interfaces help us achieve security in our application by hiding details and showing only the important details of an object(interface).
• Interface helps us overcome the problem of multiple inheritance which is not possible in C#. We cannot inherit more than one class but we can inherit more than one interface keeping in mind that we have to abide by and must provide an implementation of all the methods of all the interfaces we inherit.

Interfaces in C# was originally published in Level Up Coding on Medium, where people are continuing the conversation by highlighting and responding to this story.

Are you facing this issue on the startup of Docker Desktop? Let’s discuss how to resolve this error, “Docker Desktop is unable to detect Hypervisor” on installing the Docker desktop on Windows 11.

The issue behind this error is Virtualization or Secure Virtual Machine(SVM) is disabled in the firmware.

Check if Virtualization is disabled on your PC

In the Windows search bar type ‘Task Manager’ and open it. Go to the performance tab in the navigation tab and check if virtualization is enabled or not.

Let’s discuss how easily we quickly change this in the firmware

Step 1) Go to “Setting>Recovery>Advance Startup” and click on Restart Now.

Step 2) A new tab will appear, Choose Troubleshoot and then select Advanced options

Step 3) Select UEFI Firmware Settings. If you don’t see this icon, then press Startup Repair, instead. When your PC is restarting, tap F1 (or F2) to access the BIOS.

Step 4) Now, you will land on this page, Select Advanced Mode on the bottom left or Press F7.

Step 4) Choose the Advanced option in the navigation menu and Enable the SVM Mode. Also, if you are using an ASUS device change the UMA Frame Buffer Size to Auto instead of 512M.

Step 5) Press F10 to Save and Exit. Your system will reboot with the updated features

Check Again the Virtualization in the Task Manager. Voilà !!!Now you should be able to install Docker and run any Docker image in your Windows system.

How to enable Virtualization: Docker Installation Error was originally published in Level Up Coding on Medium, where people are continuing the conversation by highlighting and responding to this story.

Continuous Integration is an important part of DevOps, and Jenkins is the most famous and widely used tool for Continuous Integration.

What is Jenkins, and why do we use it?

Jenkins is a self-contained Java-based program with plugins built for continuous integration. Jenkins is used to build and test your software projects continuously, making it easier for developers to integrate changes.

How to Install Jenkins on Windows

1) To start configuring Jenkins on Windows, you first need Java Development Kit(JDK).

2) Set the Environment Variable path for JDK

• Search for Environment Variable in the Task Bar and click on “Edit the system environment variables”

• Under the system variables, select the “Path” variable and click on “Edit”. Click on “New” then paste the Path Address of your JDK i.e. C:\Program Files\Java\jdk-{YOUR_JDK_VERSION}\bin. Click on “OK”.

• Now, in the Environment Variables dialogue, under System variables, click on “New” and then under Variable name: JAVA_HOME and Variable value: paste address i.e. C:\Program Files\Java\jdk-{YOUR_JDK_VERSION}. Click on OK => OK => OK.

3) Now, that we have installed JDK, we have to download Jenkins LTS.

• Once it is downloaded, it will open a wizard on your screen. Click “Next” to start the Jenkins installation.

• Click on change, and I would advise you to keep things simple and don’t change the path.

• Select ‘Run service as LocalSystem” or you can also select the second option, ‘Run service as local or domain user’. I am .moving forward with the first option

• It is recommended that you accept the selected default port. Test the port and click on the “Next” button.

• Select the Java home directory, and then click on the “Next” button.

• Click on the “Next” button.

• Click on the Install button to start the installation process.

• When done, click on “Finish” to complete the installation process. Now that the installation process is out of the way, you need to follow a few more quick steps before you start using Jenkins on Windows.

Unlock Jenkins For Windows

• Paste the URL http://localhost:8080 in a browser or change the port if you changed it in the installation process.

• Go to the path specified, you will get the initial password there, paste it here and click on the ‘Continue’ button.
• Next, Install the suggested plugins

• The plugins will be installed and will take some time, be patient.

• Click on ‘Save and Finish’ button and you will be redirected to the admin page of Jenkins.

• Finally, here is the default Jenkins page. Jenkins is now installed and running on Windows, and you are ready to start building your CI/CD pipeline.

• Finally, here is the default Jenkins page. Jenkins is now installed and running on Windows, and you are ready to start building your CI/CD pipeline. ( The initial password used above is the admin password.)

Conclusion

Now, you can install Jenkins on Windows and start creating your continuous integration pipeline. You are well on your way to becoming a DevOps and CI/CD expert.

How to Install Jenkins: Complete Step by Step guide was originally published in Level Up Coding on Medium, where people are continuing the conversation by highlighting and responding to this story.

For now, Let’s see how Github Copilot and ChatGPT are used as a tool in software development:

GitHub Copilot: With GitHub Copilot, more than 1.2 million developers rely on AI to generate code on their behalf, saving them time.

Copilot uses machine learning algorithms and natural language processing to examine code patterns and provide suitable suggestions. It uses the code available on GitHub and suggests code snippets that increase productivity and efficiency by reducing the time and effort required to write code.

ChatGPT: I am sure you have heard of ChatGPT and probably used it too. ChatGPT is an AI-powered chatbot that uses a deep learning model designed for natural language processing tasks, Phew!

In basic terms, It can generate human-like responses to text-based input (Wait for ChatGPT 4, it will blow your mind).

And now, you may ask, How it helps a software developer?

1. Show the HTML for the login form.

2)How to use redux in React?

3)How can I connect the .Net backend with the Angular frontend?

With the above three examples, you can see the power of ChatGPT and how it can be used. Yes, there are limitations to it but you get the idea right.

Developer VS Developer using AI

I have been working in a multinational software development company for more than a year now, and what I realized is that a developer using AI, such as Github Copilot or ChatGPT, will increase a developer’s productivity and efficiency. Either you can write the HTML for the login form or get it from chatGPT in a few seconds, write your code, or use copilot that can suggest and predict the next line of code based on context, allowing developers to write code faster and with fewer errors.

The choice is yours, as the person next to you can use AI and will most likely do a better job than you. As the title says, AI will not take your job, but a person using AI will.

AI will not take your job, But a person using AI will was originally published in ILLUMINATION on Medium, where people are continuing the conversation by highlighting and responding to this story.