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done with basics
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# C# Crash Course
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In this C# Crash Course, we'll go over the basics of C# so that you'll be ready to build out exciting web apps in emails 3, 4, and 5! We'll start by going through the key attributes of C#, syntax basics, and introduce you to OOP. At the end, we'll link you to some quick in-browser C# challenges so you can apply these concepts.
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In this C# Crash Course, we'll go over the basics of C# so that you'll be ready to build out exciting web apps in emails 3, 4, and 5! We'll start by going through the key attributes of C#, syntax basics, and introduce you to OOP. In each section, we'll link you to some quick in-browser C# challenges so you can apply these concepts.
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## Topics you'll learn
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* Language attributes
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* Strongly typed
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* Compiled languages
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* Syntax basics
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* Keywords
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* Accessing methods
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* Parameters
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* Semicolons
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* Data types
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* Variables
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* Arithmetic operators
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* Booleans
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* Object Oriented Programming
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* Records
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* Objects
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* Properties
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* Methods
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# Let's get into it!
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## Language Attributes
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---
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# Language attributes
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C# is a strongly typed, compiled, object oriented language. Let's break this down.
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* In a **strongly typed** language, every variable has a defined type. Every method declaration specifies a name, the type and kind for each input parameter and for the return value.
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* A **compiler** converts the code you write into a format that your computer can understand.After you write C# and build it, the C# compiler (called Roslyn) will analyze your code to check for any errors.
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## Strongly typed
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In a **strongly typed** language, every variable has a defined type. Some of these types include:
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* String, "Hello world!"
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* Char, 'a'
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* int, 3
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* decimal, 1.5
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* bool, True
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## Syntax Basics
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## Compiler
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A **compiler** converts the code you write into a format that your computer can understand.After you write C# and build it, the C# compiler (called Roslyn) will analyze your code to check for any errors.
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---
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# The basics
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Here's a piece of code that will print "Hello world!" to the console.
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```csharp
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Console.WriteLine("Hello world!");
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```
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### Keywords
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## Keywords
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With C#, you use **keywords** like *using* and *Console*.
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>Keywords are predefined, reserved identifiers that have special meanings to the compiler.
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**Keywords** are predefined, reserved identifiers that have special meanings to the compiler.
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### Accessing methods
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## Accessing methods
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The Dot in *Console.WriteLine* allows us to access methods and properties. In this example, **Console** is a type that represents the console window. **WriteLine** is a method of the Console type that prints a line of text to that text console.
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### Parameters
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## Parameters
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In this example, we use parentheses pass a string as a parameter to *Console.WriteLine*.
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## Variables
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In C#, **variables** allow you to temporarily store a value in memory. In C#, you must declare a vaiable before using it.
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```csharp
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var cSharp = "really cool";
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```
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In this example, we created a string called *cSharp*. You can use the var keyword to declare local variables without explicitly giving them a type.
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Variable names can contain alphanumeric characters and underscores, but no special characters. They also cannot be keywords.
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...
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## OOP
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C# is an object-oriented language. You define types and their behavior.
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...
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## Syntax cheat sheet
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1. Every statement is ended by a semicolon
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```csharp
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Console.WriteLine("there is a ';' at the end of this statement");
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```
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1. You can make comments by using 2 slashes
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```csharp
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// this is a comment is C#
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```
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1. C# is case sensitive! For example, a variable "cat" is completely different from a variable "CAT".
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```csharp
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var cat = "meow";
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var CAT = "rawr";
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```
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1. Arithmetic operators
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These are probably familiar to you!
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| symbol | what it does |
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| --- | ------ |
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| + | addition |
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| - | subtraction |
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| * | multiplication |
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| / | division |
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| % | remainder |
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| ++ | increment |
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| -- | decrement |
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2. Boolean expressions
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We use booleans to compare two or more things.
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| symbol | what it does |
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| --- | ------ |
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| < | less than |
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| > | greater than |
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| <= | less than or equal |
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| >= | greater than or equal |
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| == | equal |
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| != | not equal |
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---
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# OOP
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C# is an object-oriented language.
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Objects are defined by **Classes**. In other words, an **Object** is an instance of a class.
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One way to think about this is that a class is like the blue prints for a house. The actual house that is built is an objects because it is an instance of this blue print.
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Objects inherently have attributes. In C# we call these **properties**. The attributes of a house may be the number of doors, what color the house is painted, etc.
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We can also define **methods** which describe what an object can do. For example, you can sell your house.
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Let's look at an example House class:
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```csharp
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// The namespace declaration provides a way to logically organize your classes
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namespace Classes;
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public class House
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{
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// House properties
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public string Address { get; }
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public int Size { get;}
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// House methods
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public void SellHouse(decimal amount, DateTime date)
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{
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}
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}
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```
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We can define a **constructor** to allow us to create new House objects.
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```csharp
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public House(string address, int squareFeet)
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{
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this.Address = address;
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this.Size = squareFeet;
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}
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```
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When we create an object with **new** this constructor will be called.
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```csharp
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using Classes;
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// Let's create a 1500 square foot house on Candy Cane Lane
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var house = new House("123 Candy Cane Lane", 1500);
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```
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# Mini Challenges!
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Each of these mini challenges is designed so that you can apply C# concepts to mini coding exercises. These challenges are all sourced from Microsoft documentation and will allow you to get coding inside your browser. Easy peasy!
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@ -57,7 +141,8 @@ Each of these mini challenges is designed so that you can apply C# concepts to m
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|-| ------------------------------- | ------------------------------- | ----------- | -------------------------------------- | - |
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1 | [Hello World](https://docs.microsoft.com/learn/modules/csharp-write-first/2-exercise-hello-world/?ns-enrollment-type=learningpath&ns-enrollment-id=learn.languages.csharp-first-steps)| N/A | 3 min | case sensitive, strings, comments | [Intro to C# Tutorial](https://docs.microsoft.com/dotnet/csharp/tour-of-csharp/tutorials/hello-world?WT.mc_id=csharpnotebook-35129-website), [C# documentation](https://docs.microsoft.com/dotnet/csharp/) |
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2 | [Variables](https://docs.microsoft.com/learn/modules/csharp-literals-variables/6-challenge )|[Solution](https://docs.microsoft.com/learn/modules/csharp-literals-variables/7-solution)| 5 min | variables, data types, strings, ints, decimals | [Numberic Types](https://docs.microsoft.com/dotnet/csharp/tour-of-csharp/tutorials/numbers-in-csharp?WT.mc_id=csharpnotebook-35129-website), [C# documentation](https://docs.microsoft.com/dotnet/csharp/) |
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3 | [Challenge](...)|[Solution](...)| 5 min | topics | [Link](...) |
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3 | [Operating on Numbers](https://docs.microsoft.com/learn/modules/csharp-basic-operations/5-challenge)|[Solution](https://docs.microsoft.com/learn/modules/csharp-basic-operations/6-solution)| 2 min | ints, decimals | [Link](...) |
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4 | [Challenge](...)|[Solution](...)| 5 min | topics | [Link](...) |
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# Bonus and more ways to connect
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