Project Link: GitHub
Setting up the Project in Visual Code via Command Line
> mkdir InheritanceVsInterfaces
> cd InheritanceVsInterfaces
Create a solution
> dotnet new sln
The template "Solution File" was created successfully.
This will create the solution name the same as container folder name
Create a console app
> dotnet new console -o II.ConsoleApp
The template "Console App" was created successfully.
Processing post-creation actions...
Running 'dotnet restore' on C:\data\InheritanceVsInterfaces\II.ConsoleApp\II.ConsoleApp.csproj...
Determining projects to restore...
Restored C:\data\InheritanceVsInterfaces\II.ConsoleApp\II.ConsoleApp.csproj (in 179 ms).
Restore succeeded.
Add console app to the solution
> dotnet sln add II.ConsoleApp
Project `II.ConsoleApp\II.ConsoleApp.csproj` added to the solution.
Create a C# class libaray project
> dotnet new classlib -o II.Library
The template "Class Library" was created successfully.
Processing post-creation actions...
Running 'dotnet restore' on C:\data\InheritanceVsInterfaces\II.Library\II.Library.csproj...
Determining projects to restore...
Restored C:\data\InheritanceVsInterfaces\II.Library\II.Library.csproj (in 128 ms).
Restore succeeded.
Add library to the solution
>dotnet sln add II.Library
Project `II.Library\II.Library.csproj` added to the solution.
Add reference to II.Library in II.ConsoleApp
> dotnet add II.ConsoleApp/II.ConsoleApp.csproj reference II.Library/II.Library.csproj
Reference `..\II.Library\II.Library.csproj` added to the project.
II.ConsoleApp.csproj
<Project Sdk="Microsoft.NET.Sdk">
<ItemGroup>
<ProjectReference Include="..\II.Library\II.Library.csproj" />
</ItemGroup>
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net6.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
</Project>
II.Library.csproj
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>net6.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
</Project>
Restoring the Projects
> cd II.ConsoleApp
InheritanceVsInterfaces\II.ConsoleApp
> dotnet restore
Determining projects to restore...
All projects are up-to-date for restore.
> cd II.Library
InheritanceVsInterfaces\II.Library
> dotnet restore
Determining projects to restore...
All projects are up-to-date for restore.
Run the console app
either CD into console app and isseue
> dotnet build
> dotnet run
or from the main folder
> dotnet --project II.ConsoleApp/II.ConsoleApp.csproj
Actions at solution level in folder InheritanceVsInterfaces
> dotnet clean
> dotnet build
Actions inside II.ConsoleApp
> dotnet clean
> dotnet build
> dotnet run
> dotnet watch run
Project Notes
- Inheritance is not code sharing
- Is-a relationship
- Need to share common logic
- Sharing just properties or method signature is not enough
- Inheritance can put you in a corner
- You need to ask the question: What is the point?
We have cornered ourselves with II.Library.FaultyOO implementation
- Style so moved it to RentalCars and RentalTruck. Removed for RetalBoat and RentalSailBoat
- StartEngine and StopEngine do not apply to RentalSailBoat. So made these virtual and override will throw exception in RentalSailBoat. Which means we'll need to check the implementation throughout the code to check for the object with "is"
A better approach is detailed in II.Library.BetterOO implementation
