C-sharp-fundamentals

This repo is created to track and record learning C#

HelloWorldApplication

• Learn how to create a C# (.Net Framework) console app
• Learn about Console.Write, Console.WriteLine(), Console.ReadLine() methods
• Learn how to build and run C# app

Module02Lesson02Variables

• Learn about different types of variables (string, int, double, decimal, boolean)
• Learn to declare a variable
• Learn to use a variable
• Strings (Learn about escaping characters, string literal, string interpolation)
• Difference between double and decimal
• Identify when to use int and string

Module02Lesson02VariablesExcercise

This app was created to implement learning from Module02Lesson02Variables and uses following C# features

• Use Console.Write to output message
• Use Console.ReadLine() to collect data from user and assign it to variable
• Use bool and while loop to collect age data from user
• Use int.TryParse() method to convert string into integer age
• Use Console.Clear() to clear console screen

Module02Lesson03Conditionals

• Learn about if / else if / else conditonal statements
• Learn about &&, ||, == operators
• Learn about switch statements
• Learn about .ToLower() method

Module02Lesson03ConditionalsExcercise

• Practise if else conditional statements
• Console app to welcome Tim Corey as professor and others as students

Module02Lesson04Conversion

• Convert string to int
• Learn how to use int.TryParse and int.Parse methods
• Combining int.TryParse methods with if/else conditions

Module02Lesson04ConversionExcercise

• Console app asks for user age and calculates how old user was in the year 2000
• While loop is used to ensure correct age is entered by user
• if / else statement is used to display results

HomeWorkConditionalsConversion

• Mini project to practise if/else conditon
• Convert string to int
• Perform subtraction operation on string interpolation
• Practise writing pseudocode

Module02Lesson06Loops

• While Loop (runs 0 or more times)
• Do while loop (runs 1 or more times)
• Looping is important to ensure user enters correct data or to perform any kind of validation

Module02Lesson06LoopsExcercise

• Ask for the users name. If users name is Tim, say "Hello Professor" otherwise, say hi username until they type exit
• Do while loop is chosen as the code needs to run at least once
• If / else statemennt is used inside loop for conditional check

Module02Lesson07Arrays

• Create Array
• Different ways of creating arrays
• Accessing array element
• Array length and indexing

Module02Lesson07ArraysExcercise

• Console app to create an array with three names
• User selects number 1 to 3 and respective name is displayed based on first, second and third name in an array
• Learn how to use and access array

Module02Lesson08Lists

• how to create lists
• advantages of lists
• how to add data to lists
• how to remove elements from lists
• how to replace elements from lists

Module02Lesson08ListsExcercise

• Console app to add students until there are no more students to add
• uses while loop to check if user wants to add students or not
• uses while loop to collect correct data format
• adds student names to the list if the user wants to add student to list

Module02Lesson09Dictionary

• How to create key value pairs
• How to check if key is present
• How to access value of key
• Keys must be unique, if same then it will overwrite previous values

Module02Lesson09DictionaryExcercise

• Console app: Create a dictionary with id and name
• ask user for id and display the name
• check the id is correct, a number and is within range
• re-prompt user for id if id is incorrect

Module02Lesson10ForLoop

• How to use for loop
• How to increase and decrease for loop
• How to use for loops with arrays and lists

Module02Lesson10ForLoopExcercise

• Console App that asks username seperated by commas
• Regex set up to remove all whitespaces, tabs
• Split user input and assign it to an array
• Print the contents of array using for loop

Module02Lesson11ForEach

• How to use forEach
• When to use forEach
• Use forEach as much as possible with lists, arrays

Module02Lesson11ForEachExcercise

• Console App that asks firstname
• adds user input into list
• then displays the user input using foreach loop

Module02Lesson12Methods

• Learn how to use methods
• why methods are important
• Concept of DRY Do not repeat yourself
• Global variables
• How to create and call methods

Module02Lesson12MethodsExcercise

• Console app to create two methods
• One method asks user for username
• Another method welcomes user by printing "Hello username"

UsingBreakPointsDemo

• Create breakpoint by clicking the grey area
• Use locals to watch the existing variables
• Create breakpoints at different points
• Remove breakpoints by clicking on the breakpoint or Debug > Toggle Breakpoint

ExceptionHandlingDemo

• How to handle exception using try and catch
• Try tries to execute a code
• catch catches and error and throws exception

AdvancedExceptionDemo

• Different types of exception
• Use try catch

AdvancedBreakpointsDemo

• Deal with advanced breakpoints
• Add conditions to breakpoints
• Add action and log to breakpoints
• import and export exceptions

Module04StaticClassesDemo

• how to create static classes
• importance of public classes
• why static classes are important
• use class files to seperate code

Module04StaticClassesDemoExcercise

• Create a console app with static class that handles calculations
• Create different classes

Module04InstantiatedClassDemo

• Instantiate class
• Purpose of instantiating data

Module04InstantiatedClassDemoExcercise

• Console app that has a person class and an address class
• Instantiate class
• Create class
• Use class in method

Module04PropertyTypesDemo

• Difference between auto prop and full prop
• Use full prop when data needs to be masked or filtered/checked
• As a default always use auto props

Module04PropertyTypesDemoExcercise

• Console app that has properties for street address, city, state and zip code
• Then add a FullAddress property that is read-only

Module04ClassLibraryDemo

• Importance of class library
• how to reference class library to user interface
• put as much code as possible into class library
• do not put user interface code to class library (for e.g. console.writeline and readline etc)

Module04ClassLibraryDemoExcercise

• Try to make a console app without looking at the tutorial

Battleship app

• Create a battleship console app
• Use all the concepts up to module04
• Follow tutorial and complete challenges
• Complete methods challenges

Module06InheritanceDemo

• Define inheritance (special class which can be passed down to other class)
• When to use inheritance (whenever property is a relationship inheritance should be used)
• When not to use inheritance (if a property does not apply we should not inherit it)
• Cannot inherit directly from more than one class

Module06Lesson04InheritanceMiniProject

• Miniproject that uses inheritance and interface
• Interface can be used to connect non related items together

Module06Lesson05AccessModifiersDemoApp

• Different types of modifiers and its usage

Module06Lesson06AbstractClassDemoApp

• How to create Abstract class

Module06Lesson07MethodOverRidingDemoApp

• How to create method overiding

Module06Lesson07MethodOverRidingDemoAppExcercise

• Excercise to practise overiding

Module06Lesson08CardGameUIApp

• Mini project to implement abstract, access modifier, enums

Module06Lesson09MethodOverloadApp

• Method overload means having multiple methods with same name but different parameters
• Can have two methods with same name as long as their signatures are different
• Method overload allows us to have different configuration set up for a method
• method overload is ideal when
  • performing same operation with different data types
  • providing flexibility in input
  • improving code readability and input

Module06Lesson10ExtensionMethodDemo

• What is a extension method ?
  • Way to add additional functionality to an existing class without modifying its source code or creating a new derived class.
  • Simple analogy: Shoes which is functional but you want it to be waterproof. Instead of creating shoes from scratch you can just add a waterproof spray. Waterproof spray is like an extension method.
• How to create an extension method ?
  • step 1: Create a static class (helper container)
  • step 2: Inside that static class create a static method. First parameter of method starts with "this" keyword
  • step 3: Populate the method as required. Once complete method becomes and use it using dot notation (e.g. variable.ExtensionMethod())
• Why and When to use extension class ?
  • When you don't have access to source code or you don't own class but you want to add functionality, e.g. extension method to add data to database
  • To keep your code clean as you don't need to create subclasses or modify source code
  • Make code more readable by calling methods directly on the objects they relate to

Module06Lesson10ExtensionMethodDemoExcercise

• Create the following chain using extension methods person.SetDefaultAge().PrintInfo()
  • In this example default age has been set as 18 and provided as an optional parameter

Module06Lesson11ExtensionMethodsMiniProject

• MiniProject to practise extension method and method overloading

Module06Lesson11ExtensionMethodsMiniProject2

• Practice extension method and method overloading without looking at solution

Module06Lesson12GenericsDemo

• What is a generic item ?
  • Generic item allows us to define classes, methods, and data structures that can operate with any data type while maintaining type safety. So this works with any datatype we provide.
• Why do we need Generics ?
  • We need generics to ensure type safetey i.e. ensure compile time type checking and prevent runtime errors
  • It also allows us to write one method or class that works with any data type
  • It also increases the performance as it avoids boxing/ unboxing for value types
• How do we create Generics ?
  • We create generics by adding to class and methods

##Module06Lesson12GenericsDemoExcercise

• Excercise to practice Generics

##Module06Lesson13EventDemoApp

• What is an event Listener ?
  • Event listener listens to changes in state and can reports back so we know state has changed. e.g. if we are loading a lot of data in the background and wanted to let the user know when done then we can use event listener.
• Why do we need event listener ?
  • Whenever the state of object changes we will need event listener to notify the state has changed.
• How do we create an even listener
  • There is three parts to event handlers.
    • Declaration - must be done in class where the model will be invoked, syntax - public EventHandler EventHandlerName
    • Listener - must be done in Main class, syntax - Object.EventHandlerName += EventHandler_Name
    • Invokation - must be done inside method where it is to be triggered upon meeting certain condition, syntax EventHandlerName?Invoke(this, message)

##Module06Lesson13EventDemoAppExcercise

• Create an event in a class and then consume that class. Attach a listener to the event and have it wire to the console
  • Event listener created to notify user if stock ISA portfolio is greater than 20k.

##Module07Lesson04UnitTestDemoLibraryApp

• Unit test using XUnit
• Unit test tests is only intended to test one unit of work (i.e. one method)
• Unit test only tests public methods
• You should not test your dependencies, it must be independent of email, database, we just want to test the logic
• Use [Fact] if you only want to test once, if you want to run multiple tests use [Theory] and [InlineData(params)]
• Unit test should have these features
  • Arrange: Instantiate a class
  • Act: Call upon the method to be tested
  • Assert: Compare the expected and actual

##Module07Lesson04UnitTestDemoLibraryExcerciseApp

• Create a fizzbuzz class library with a method
  • that returns Fizz if divisible by 3
  • that returns Buzz if divisible by 5
  • that returns FizzBuzz if divisible by 3 & 5
  • else that returns string of the number
• Create unit test using XUnit

##Module07Lesson05ClassLibraryUnitTestExcerciseApp

• Create a math operation class library
  • that adds, subtracts, multiplies, divides two numbers
• Create unit test using XUnit