First C# Program

Here, you will learn to create a simple console application in C# and understand the basic building blocks of a console application.

C# can be used in a window-based, web-based, or console application. To start with, we will create a console application to work with C#.

Open Visual Studio (2017 or later) installed on your local machine. Click on File -> New Project... from the top menu, as shown below.

Create a New Project in Visual Studio 2017

From the New Project popup, shown below, select Visual C# in the left side panel and select the Console App in the right-side panel.

Select Visual C# Console App Template

In the name section, give any appropriate project name, a location where you want to create all the project files, and the name of the project solution.

Click OK to create the console project. Program.cs will be created as default a C# file in Visual Studio where you can write your C# code in Program class, as shown below. (The .cs is a file extension for C# file.)

C# Console Program

Every console application starts from the Main() method of the Program class. The following example displays "Hello World!!" on the console.

Example: C# Console Application
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CSharpTutorials
{
    class Program
    {
        static void Main(string[] args)
        {
            string message = "Hello World!!";

            Console.WriteLine(message);
        }
    }
}

The following image illustrates the important parts of the above example.

C# Code Structure

Let's understand the above C# structure.

  1. Every .NET application takes the reference of the necessary .NET framework namespaces that it is planning to use with the using keyword, e.g., using System.Text.
  2. Declare the namespace for the current class using the namespace keyword, e.g., namespace CSharpTutorials.FirstProgram
  3. We then declared a class using the class keyword: class Program
  4. The Main() is a method of Program class is the entry point of the console application.
  5. String is a data type.
  6. A message is a variable that holds the value of a specified data type.
  7. "Hello World!!" is the value of the message variable.
  8. The Console.WriteLine() is a static method, which is used to display a text on the console.
Note:
Every line or statement in C# must end with a semicolon (;).

Compile and Run C# Program

To see the output of the above C# program, we have to compile it and run it by pressing Ctrl + F5 or clicking the Run button or by clicking the "Debug" menu and clicking "Start Without Debugging". You will see the following output in the console:

Output:
Hello World!!

So this is the basic code items that you will probably use in every C# code.