Getting Started with .NET Core and C# Programming

A couple of months ago, I started working on new projects that required me to learn C# to deliver excellent results at my job. Now, I am here to save you from tutorial hell and roadblocks by sharing everything I’ve learned in a simplified manner for any novice trying to master C#. This article is the first in the "Mastering C#" series, covering essential concepts to ensure your understanding.

Pre-requisites

Before diving into this guide, ensure you have the following prerequisites:

• Basic Programming Knowledge:
  Familiarity with fundamental programming concepts such as variables, loops, and functions.

• Development Environment Setup:

  • Install the latest version of .NET Core SDK from the official .NET website.

  • Install a code editor like Visual Studio Code or Visual Studio.

• Understanding of Object-Oriented Programming (OOP):
  Basic knowledge of OOP principles such as classes, objects, inheritance, and encapsulation.

• Command Line Basics:
  Ability to navigate and execute commands in the command line or terminal.

• Internet Access:
  For downloading necessary tools and libraries, and accessing documentation and resources.

These prerequisites will help you get the most out of this guide as you explore .NET Core and C#.

Table of Contents

• Introduction to .NET Core and C#

• Overview of .NET Core and its features

• Differences between .NET Framework and .NET Core

• Creating a simple .NET Core application with C#

Introduction to .NET Core and C

.NET Core is a cross-platform, open-source framework developed by Microsoft. It allows developers to build modern, scalable, high-performance applications for various platforms, including Windows, macOS, and Linux.

C#, a versatile and powerful programming language, is at the heart of .NET Core development, providing robust features for building various applications, from web and desktop applications to mobile and cloud services.

Overview of .NET Core and its Features

So, what makes .NET Core so cool? It offers several features that make it an excellent choice for modern application development:

• Cross-Platform Compatibility:
  You can develop and run your apps on Windows, macOS, and Linux.

• Performance and Scalability:
  It is built for speed and can handle scaling up your apps.

• Modular and Lightweight:
  Applications can be optimized by including only the necessary components. (i.e., only use what you need, keeping your apps lean and mean.)

• Unified Development:
  A single platform for building web, desktop, mobile, cloud, gaming, IoT, and AI applications. For example, with ASP.NET Core, developers can build scalable web apps using the MVC pattern and deploy microservices or serverless functions on cloud platforms like Microsoft Azure..

• Open Source and Community-Driven:
  Contributions from developers around the world help in the continuous improvement of .NET Core.

Differences between .NET Framework and .NET Core

Understanding the key differences between .NET Framework and .NET Core is crucial for making informed decisions about your development projects:

• Cross-Platform vs. Windows-Only:
  .NET Core enables developers to write applications that can run on Windows, macOS, and Linux, expanding the reach of their software beyond Windows users. This versatility allows developers to target a broader audience and deploy applications on diverse operating systems without major changes to the codebase.

• Performance:
  .NET Core is optimized for speed and scalability, making it suitable for high-performance applications. For example, ASP.NET Core, built on .NET Core, handles high traffic efficiently due to its lightweight and modular design, which translates to faster response times and better resource utilization compared to .NET Framework.

• Deployment:
  With .NET Core, developers can deploy applications in various ways, including self-contained deployments, which package the runtime and libraries, ensuring compatibility and reducing dependencies. For instance, deploying a .NET Core application as a Docker container simplifies deployment across different environments.

• Development and Updates:
  .NET Core's agile development cycle with frequent updates gives developers early access to new features, security patches, and performance optimizations. For example, .NET Core 3.0 introduced major performance improvements and new features like Windows desktop support and Blazor for interactive web UIs.

Creating a Simple .NET Core Application with C

In this section, I will walk you through setting up a .NET Core project and writing your first C# application. By the end, you will know how to set up your environment, write some code, and run your app.

1. Set Up Your Development Environment

Once you have installed the necessary software from the pre-requisites section:

• Open Visual Studio Code (or Visual Studio if you choose that).

• Create a New Project: In Visual Studio Code, open the integrated terminal (Ctrl + `) and navigate to the directory where you want to create your project.

    mkdir MyFirstDotNetApp
    cd MyFirstDotNetApp
  

• Initialize a New .NET Core Console Application:
  Use the following command to create a new .NET Core console application:

    dotnet new console
  

  The command dotnet new console is used in .NET Core to create a new console application project. When you run this command in your terminal or command prompt, it generates the necessary files and folders to start a basic console application project using C#. This includes setting up a Program.cs file with a default "Hello World" program, which you can then build and run using other .NET Core commands (dotnet build and dotnet run).

2. Write Your First C# Code

• Open the Project in Your Code Editor:

  If you are using Visual Studio Code, type:

    code .
  

  This command opens the current folder in Visual Studio Code.

• Explore the Project Files:
  You'll see a file named Program.cs. This file contains the entry point and main logic of your application.

• EditProgram.cs:
  Replace the existing code in Program.cs with the following:

    using System;
  
    namespace MyFirstDotNetApp
    {
        class Program
        {
            static void Main(string[] args)
            {
                Console.WriteLine("Hello, World!");
            }
        }
    }
  

  This simple program outputs "Hello, World!" to the console.

3. Build and Run Your Application

• Build the Project:
  In the terminal (integrated terminal in Visual Studio Code), run the following command to build your application:

    dotnet build
  

  This command compiles your C# code into an executable.

• Run the Application:
  After successfully building the project, run your application using the following command:

    dotnet run
  

  You should see the output:

    Hello, World!
  

The output "Hello, World!" appears in the terminal or command prompt itself. When you run a console application that prints "Hello, World!" using Console.WriteLine("Hello, World!"); in C#, the text is displayed directly in the same terminal or command prompt window from which you executed the dotnet run command.

Congratulations! You have successfully created and run your first .NET Core application using C#. You can now explore further by modifying Program.cs, adding more functionality, or exploring other features of .NET Core and C#.

I truly hope you have learned a thing or two. Next up in the "Mastering C#" series, is the Mastering LINQ in C#. Happy coding!