C# Basics for Beginners: Learn to Write and Run Your First Program

Welcome to the world of C#! In this section, we’ll introduce you to the fundamentals of writing your first program, understanding the structure of a C# program, and running your code. By the end of this section, you’ll feel confident writing your first few lines of code.

Understanding Your First Program (Hello World)

The classic way to begin learning any programming language is by writing a simple program that displays “Hello World” on the screen. Here’s how you can do it step by step:

• Open Your IDE: Use an IDE like Visual Studio or Visual Studio Code. Create a new C# console application.
• Write the Code: Type the following code into the editor:

• Run the Program: Click the "Run" or "Start" button in your IDE. You should see "Hello, World!" printed on the console.

.Breaking Down the Code:

• using System; : This line tells the program to use the System namespace, which provides classes for basic operations like input and output.
• namespace HelloWorldApp: A namespace is like a container for your code. It helps organize and avoid naming conflicts.
• class Program: A class is the blueprint of your program. Here, Program is the name of the class.
• static void Main(string[] args): This is the entry point of every C# application. When you run the program, the code inside the Main method is executed.
• Console.WriteLine("Hello, World!");: This line prints the text "Hello, World!" to the console. Console is a class, a method that writes a line of text.

Syntax and Structure of a C# Program

Understanding the structure of a C# program is essential for writing error-free code. Let’s break it down:

Core Structure:

• Namespaces: Organize your code and prevent naming conflicts.

using System;        

• Classes: Contain your program’s code.

class Program
{
    // Code goes here
}        

• Methods: Define actions that your program can perform.

static void Main(string[] args)
{
    Console.WriteLine("Hello, World!");
}        

• Statements: Perform actions, like displaying text or performing calculations. Each statement ends with a semicolon.

Key Syntax Rules:

• Case Sensitivity: C# is case-sensitive. Main and main are different.
• Semicolons: Every statement must end with a semicolon (;).
• Indentation: While not mandatory, proper indentation makes your code easier to read.

Example:

using System;

namespace ExampleApp
{
    class Example
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Welcome to C#!");
        }
    }
}        

Writing and Running Programs

Here’s how you can create, save, and run a basic C# program:

Step-by-Step Guide:

• Create a New Project:

a.) Open Visual Studio.

b.) Select "Create a new project."

c.) Choose "Console App (.NET Core)" or "Console App (.NET Framework)."

• Write the Code:

a.) Replace the default code with your own (e.g., the "Hello World" program)

• Save the File:

a.) Save your file with a .cs extension (e.g., Program.cs).

• Run the Program:

a.) Press F5 or click the "Run" button.

Common Mistakes and Troubleshooting:

• Missing Semicolon: Ensure every statement ends with a semicolon.
• Mismatched Braces: Every opening brace { must have a corresponding closing brace }.
• Typos: Double-check your spelling, especially for keywords like Console and WriteLine.
• File Not Saved: Make sure you save your file before running it.

Citations and References

1. Microsoft Documentation - C# Programming Guide The official documentation by Microsoft offers a comprehensive guide to C# programming, including the structure of programs and syntax explanations.
2. Microsoft Visual Studio Documentation Guides on setting up and running projects in Visual Studio, covering IDE usage and debugging tools.
3. C# Basics - TutorialsPoint A beginner-friendly explanation of core C# concepts like namespaces, classes, methods, and syntax.
4. C# for Beginners - W3Schools Offers practical examples and explanations for beginners in C#, including "Hello World" programs.
5. Books on C# Programming
6. Stack Overflow Discussions Community-driven troubleshooting tips for common C# programming errors like missing semicolons or mismatched braces.