Adedoyin-Emmanuel/csharp-journey

Learning C# from zero to hero

Learning C# 🚀

Hello there, I created this repo to document my journey on learning C# from zero to hero. Of course I learned C# from the best so why wouldn't I be a world class C# Developer. I started learning C# January 2024 and my goal is to master the language and start building solid projects by August 2024

Projects

Below are the projects that I've build with Csharp and Dotnet. I will still be building more projects as I learn more about the framework.

1. Taskify (Task management application) - Taskify Repo
2. Buka (Recipe sharing platform) - Buka Repo

Resources 👜

Okay, so for the resources, I'm learning from Mosh Hamedani, you can find the video on Youtube. But since the course is kinda old too and somethings have changed in the C# community, I'm also using the official Microsoft Documentation and their videos to learn too. I've picked somethings Mosh didn't mention there. I'm also using W3Schools to learn too, I've finished their tutorial and I also took their test and got 22/25.

1. Mosh Hamedani C# For Beginners Watch on Youtube
2. Mosh Hamedani DotNet Tutorials Watch on Youtube
3. Microsoft C# Step by Step Tutorials Microsoft C# Tutorials
4. Take W3School C# Quiz Take The Quiz
5. Learn C# Basics from W3schools Learn C# Tutorials

I will also add any other resources here.

Inspirations 🤩

Although I've always loved C# since I was in Secondary School. I was learning how to play piano and I really love the C# key. I also love the C# programming language. I've always wanted to learn it but I never had the chance to learn it. I've always been a JavaScript and TypeScript developer. I've always wanted to learn C# and build fullstack applications with it. I'm inspired by Mosh Hamedani and Scott Hanselman. I love their work and I want to be like them. I want to be a world class C# developer. I want to build amazing applications with C# and Blazor. I want to build amazing API's with ASP.NET

What I've learned 🧠

C# is an amazing language created by Microsoft decades ago. I love C# because it is a High level language.Top that it is a typed language.

1. I've learned the C# basics like intializing a project with dotnet CLI tool, declaring variables, constants, functions as well as string methods, datetime methods, arrays, array methods, lists, list methods, conditonal statement, loops, namespaces, using statements, working with files, reading a file, File static class which provides static methods, FileInfo class, methods and properties, the difference between these methods, same as Directory class and DirectoryInfo class.

2. I just moved to intermediate about 3 days ago. That's on Tuesday. (16/04/2024). And I used C# to create my 0-c#-intermediate directory and file. Which was mind blowing. I've been working with Classes and I just realized that everything in C# is classes. I've learned difference between a Class and an Object, constructors and conctructors overloading which is a new stuff. I haven't seen anything like that in JavaScript or TypeScript which are the languages I'm coming from. It is totally awesome, I learned about the constructor overloading signature concept, methods and methods overloading, access modifiers, here I also discovered C# has 2 more access modifiers that I haven't worked with before. internal and protected internal. I'm yet to learn about these modifiers but I trust they will be awesome as usual. I've also learned about the method modifiers such as params, out and ref I like the params and slighlty the ref but I think they are likely to appear in interviews than in a real world application. So I had to learn it just for that. Though my instructor Mosh Hamedani said there is a method in the Dotnet framework where you will use the out method modifier. The int.TryParse() method. So you just need to pass a out along with the value. Though I must say one weird thing I've noticed is that I get auto completions here on my Mac. But when I was still using my Linux Ubuntu, I don't get auto completions on Vscode. I don't even get any error even if I make a syntax error. It wasn't a good experience. I can't wait to learn the advance part of C#. I so much love this language. Okay so I've learned a lot since I last edited the documentation that's yesterday. I've worked with the internal and protected internal access modifiers which I would not be using any time soon. Why? well, to my understanding, the internal and protected internal access modifier works with assembly, bottomline you aren't really going to use it in a realworld application. Even Mosh Hamedani said those 2 keywords are the worse thing that has ever happend to C#. I haven't really been able to wrap my head around it. But I will soon.

3. I've learned a lot about OOP. The funny thing is that prior to learning C#. I didn't really understand some concepts in OOP until now. I didn't know how to use Composition, I've only worked with Inheritance. But I've not only learned how to work with it, I've also learned the best practices with composition and inheritance. When to use it and when not to use it. I've also learned another concept in OOP which is Polymorphism which means different forms. Basically it is the ability of a class to have or take different forms. I haven't practised it yet though.

4. Been a while since I wrote C#, glad I'm back now. I'm almost done with the C# advance course and I will move to writing backend API's and building fullstack apps with Blazor and C# soon. But what have I learned? I've learned about Delegates, Events, Generics, Extension Methods, Lambda Expressions etc. I will be practising what I've learned before moving to the next episode which is LINQ and then Asynchronous Programming. I can't wait to learn about LINQ. I've heard a lot about it. I even built a project with the name Linq. Use Linq I can't wait to learn about it. I'm so excited. Okay, I finally practised Lambda expressions, delegates and generics.

5. I've been able to practise Lambda expressions, delegates and all. I event created my own custom Func and Action delegates. I'm also understanding generics bit by bit. I'm loving C# more and more. Right now, I'm about to practise events and understand how it works. Then I will move to Extensions and then to Enums which I already know, LINQ and then to Asyncronous operations in C#.

6. I must say events in C# gave me tough time, this is because events as a whole comprises of Delegates and all, top that events are like complext delegates but I love it, hopefully I should understand it better very soon. Up next is extension methods, though I'm not a fan of this approach but I'm still going to learn and practice it.

7. Yeah, I've learned method extension, At first it looked kinda confusing, I was kinda confused about where to add the this keyword. Basically, you just add the type you want to extend in the method you want. Though there are some requirements that must be met, the extension class and methods should be marked static they must have a public access modifier. Let's try to create an Extension Method eg

using System;


namespace CSharpJourney{

    public static class StringExtension{

        public static int GetWordsCount(this string str){
            return str.Split(' ').Length;
        }
    }
}

Now, you've created an extension method that gets the length of words in a string. Now let's use it in out main program..

using System;


namespace CSharpJourney{

    public class Program{
        static void Main(string[] args){
            string[] sentence = "I love C# with all my strength";

            Console.WriteLine(sentence.GetWordsCount());
        }
    }
}

8. Bingo, we created our Extension Method. But according to my instructor Mosh Hamedani, you should only create Extension Methods when you really have to. Though as awesome as it looks, I'm not really a fan of it, but yeah it was worth learning. I will also expore creating other extension methods apart from string methods.

9. I just thought of something cool, I think you should be able to use a Lambda Expression in an Extension Method. I will try it, this time it will be a Number Extension method. Yeah it is possible, I use Lambda exression to simplify a custom Square method extended from int type.

10. I finally learned LINQ. I must say, it is the most powerful thing in C#, I haven't seen this in any other language. It is super amazing. I love both the Method way, using Lambda Expressions and the LINQ Query Syntax. Super amazing stuff. I also learned and used the Dynamic keyword in C#, the dynamic keyword makes C# kinda behave like other dynamically typed languages like JavaScript and Python. I personally don't really like it because coming from a statically typed language like TypeScript and C, I'm used to knowing the type of data I'm working with and I love it that way. But I must say, the Dynamic keyword is super powerful. It can come handy in several situations. I can't wait to learn about Asynchronous Programming, Nullable Types and Exceptions in C#, after that I will move to ASP.NET

11. I finally worked with Nullable Types, it is pretty straightfoward, just like those folks that use any in Typescript 🤣 AnyScript 😆. C# has Nullable Type generics actually Nullable<T> that takes any data type like int, string, bool etc. Optionally, you can use the ? instead of the Nullable<T>. When working with Nullable types, you've to test if they contain a value before using them. For that you can use properties like HasValue or methods like GetValueOrDefault() to test for nullability. You can also use the Non Coalescing operator ?? or the optional chaining which is also in TypeScript and JavaScript ?.

12. I worked with Exceptions exception handling and all, though this isn't something new. I do this in Typescript, JavaScript, Python, C and other language I've written over the past years. But the cool thing is that I never knew you can add multiple catch statement to get different exceptions based on the specificity. System.Exception is the base Exception class, we have other exceptions like DivideByZeroException, FileNotFoundException and a lot more, you can also extend an exception and create a custom exception.

13. I finally learned about Asynchronous Programming in C#. I must say, it is the most powerful thing in C#. I've worked with Promises in JavaScript and async/await but I must say, C# is way more powerful. I love the Task class method, the async and await keywords. I also learned about Parallel Programming in C#. I must say, it is super amazing. I can't wait to learn about ASP.NET and Blazor and start building fullstack applications with C#. I also made an API request to https://jsonplaceholder.typicode.com/todos to get a list of Todos and then print it on the terminal. It was super amazing.