Lab 04: Implement OOP principles in C# with design patterns

To Apply OOP principles in C# with design patterns for robust software architecture.

Introduction

This lab covers Object-Oriented Programming (OOP) concepts in C#, including encapsulation, inheritance, polymorphism, and abstraction [1].

Environment Setup

VS Code with C# Dev Kit Extension
.NET SDK (Latest Stable Version)
Terminal/Command Prompt

File Structure


OOPLab/
│── Program.cs
│── Models/
│   ├── Person.cs
│   ├── Employee.cs
│── OOPLab.csproj

Steps

1. Create a New C# Console App

Open VS Code, then run:


dotnet new console -o OOPLab
cd OOPLab
code .

2. Implement Encapsulation (`Models/Person.cs`)


namespace OOPLab.Models;
public class Person
{
    private string name;
 
    public string Name
    {
        get { return name; }
        set { name = value.Length > 0 ? value : "Unknown"; }
    }
 
    public Person(string name) => Name = name;
    public void Display() => Console.WriteLine($"Name: {Name}");
}

3. Implement Inheritance (`Models/Employee.cs`)


namespace OOPLab.Models;
public class Employee : Person
{
    public string Role { get; set; }
 
    public Employee(string name, string role) : base(name) => Role = role;
 
    public void ShowDetails() => Console.WriteLine($"Name: {Name}, Role: {Role}");
}

4. Implement Polymorphism (`Program.cs`)


using OOPLab.Models;
 
class Program
{
    static void Main()
    {
        Person p = new Person("Alice");
        p.Display();
 
        Employee e = new Employee("Bob", "Developer");
        e.ShowDetails();
 
        // Polymorphism: Using base class reference
        Person poly = new Employee("Charlie", "Manager");
        ((Employee)poly).ShowDetails();
    }
}

5. Run the Application


dotnet run

Additional Scopes

Implement abstract classes and interfaces.
Add method overriding and operator overloading.
Use collections (List, Dictionary) with OOP.

References

[1] Microsoft Docs: C# OOP Fundamentals.
[2] .NET CLI Guide for Console Apps.

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