My Personal Roadmap for a Junior Developer with C#

As a junior developer, there are certain skills and concepts that we expect you to have mastered. Don’t worry if it sounds like a lot - we’re here to guide you along the way!

Basics of C#

• Access Modifiers and Abstract Classes: Learn how to control who gets to use parts of your code. For example, marking a class member as private means it can only be used within the same class. An abstract class Animal can be used as a base class for class Dog : Animal but cannot be instantiated on its own.
  • public: Accessible from anywhere.
  • private: Accessible only within the same class.
  • protected: Accessible within the same class or derived classes.
  • internal: Accessible within the same assembly.
  • protected internal: Accessible within the same assembly or derived classes.
• Interfaces and Inheritance: Understand how interfaces define a contract that classes can implement. For example, interface IShape { void Draw(); } can be implemented by class Circle : IShape.
• Polymorphism and Overloading: Use polymorphism to treat objects of different classes in a similar way. For example, a Draw method can be overridden in different classes to provide specific implementations.
• Understanding Data: Get the hang of basic types like integers (int) and strings (string), learn about tuples for storing multiple values ((string, int)), and dive into generics for creating flexible, reusable code, like List<T>.
  • int: Whole numbers.
  • string: Text.
  • double: Decimal numbers.
  • bool: True or false.
• Control Flow: Master if statements for conditional logic, for loops for repeating tasks, and switch statements for multi-branching logic.
• Managing Memory: Understand how .NET cleans up unused data with garbage collection. For IDisposable, you might use it to manually release unmanaged resources, like in a class that handles file streams:.

public class FileManager : IDisposable
{
    private FileStream _fileStream;

    public FileManager(string path)
    {
        _fileStream = new FileStream(path, FileMode.Open);
    }

    public void Dispose()
    {
        _fileStream.Dispose();
    }
}

• Working with Text and Errors: Practice manipulating text with operations like concatenation or using StringBuilder for more efficient text changes.
  • string interpolation: string name = "Alice"; Console.WriteLine($"Hello, {name}!");.
  • StringBuilder: var sb = new StringBuilder(); sb.Append("Hello, "); sb.Append("World!");.

For handling errors, use a try/catch block:

try {
    /* code */
} catch(Exception e) {
 /* error handling */
}

• Playing with Collections: Explore different ways to store and manage data. For instance, using a Dictionary<int, string> to hold user IDs and names.
  • List<T>: A dynamic array.
  • Dictionary<TKey, TValue>: A collection of key-value pairs.
  • Queue<T>: A first-in, first-out collection.
  • Stack<T>: A last-in, first-out collection.

Starting with .NET Core

.NET Core is your tool for making powerful apps that work across different platforms.

• Frame the Basics: .NET Core is modern and designed for the cloud, whereas .NET Framework is the original version for Windows. .NET Standard is a set of APIs that all .NET platforms implement.
• Dependency Injection and Logging: Use dependency injection to keep your code clean and understand the Dependency Injection Lifetime: Singleton, Transient, Scoped. For example,

public class OrderService {
    public OrderService(ILogger logger) {
        _logger = logger;
    }
}

For logging, set up a logger and use it to track what happens in your app: _logger.LogInformation("Processing order.");.

First Steps for Beginners:

• Creating Simple Apps: Build a console app that prints “Hello World” to understand the basics of setting up and running a program.
• Type System Adventures: Define a custom type, and use access modifiers to protect its data.

public class Car {
    public string Make { get; set; }
    public string Model { get; set; }
}

• Data Queries with LINQ: Use LINQ to filter a list of numbers: var evenNumbers = numbers.Where(x => x % 2 == 0);.

Web Development with ASP.NET Core

If you want to make web applications, ASP.NET Core is your toolkit.

• Handling Web Requests: Configure routing to direct incoming web requests to the appropriate controllers. Example:

app.UseEndpoints(endpoints => {
     endpoints.MapControllerRoute("default", "{controller=Home}/{action=Index}/{id?}");
});

• Security and Web APIs: Implement JWT by configuring the authentication middleware in Startup.cs and using attributes to protect API endpoints: [Authorize].
• Modeling and Validation: Set up model validation using data annotations:

public class Product {
    [Required]
    public string Name { get; set; }
}

Mastering Entity Framework

Entity Framework helps you work with databases in a more straightforward way by using .NET objects.

• CRUD Operations: Add a new product to a database using EF:

context.Products.Add(new Product { Name = "Sample" });
context.SaveChanges();

• Designing Databases: Use code-first to design your database; EF will match database tables to your classes. Understand how migrations work to update your database schema.

Good Software Design

Good software design means your code is easy to maintain and build on.

• Principles and Patterns: Apply the Single Responsibility Principle (SRP) by ensuring that a class only does one thing, e.g., a LoginHandler class that only handles user logins.
• Building Strong Architecture: Use MVC to separate logic, data, and display, improving manageability of your code.

SQL Essentials

Knowing how to manage databases is crucial for any developer.

• SQL Skills: Write a query to select all users named “John”: SELECT * FROM Users WHERE FirstName = 'John';.
• Database Design: Apply normalization rules to reduce redundancy, such as storing user addresses in a separate table from user profiles.

Testing Your Code

Making sure your code works well is as important as writing it.

• Developing with Tests: In TDD, write a test before you write code—for example, a test that checks if adding two numbers returns the correct sum.
• Unit Testing: Use NUnit to test a method’s output, ensuring it matches expected results: Assert.AreEqual(4, Add(2, 2));.

With these examples in mind, you should be better equipped to understand and apply the concepts as you learn. Dive into real coding scenarios, try out examples, and make sure to always look up additional resources whenever you need more clarity on the concepts. Keep exploring and happy coding!