Computed properties in C Sharp (C#) - Mini Project: Build & Apply

Computed Properties in C#

📖 Scenario: You are creating a simple program to manage a rectangle's dimensions and calculate its area automatically.

🎯 Goal: Build a C# class with computed properties that calculate the area of a rectangle based on its width and height.

📋 What You'll Learn

Create a class called Rectangle with two properties: Width and Height.

Add a computed property called Area that returns the product of Width and Height.

Create an instance of Rectangle with specific width and height values.

Print the value of the Area property.

💡 Why This Matters

🌍 Real World

Computed properties are useful in many programs where you want to calculate values automatically without storing extra data.

💼 Career

Understanding computed properties helps you write cleaner, more efficient code in C# applications, a common skill in software development jobs.

1

Create the Rectangle class with Width and Height properties

Create a public class called Rectangle with two public auto-implemented properties: Width and Height, both of type double.

C Sharp (C#)

public class Rectangle
{
    // Your code here
}

Need a hint?

Use public double Width { get; set; } and similarly for Height.

2

Add the computed property Area

Inside the Rectangle class, add a public computed property called Area of type double that returns the product of Width and Height using only a getter.

C Sharp (C#)

public class Rectangle
{
    public double Width { get; set; }
    public double Height { get; set; }
    
    // Add the computed property Area below
    // Your code here
}

Need a hint?

Use expression-bodied property syntax: public double Area => Width * Height;

3

Create an instance of Rectangle with specific dimensions

In the Main method, create a variable called rect and assign it a new Rectangle object with Width set to 5.0 and Height set to 3.0.

C Sharp (C#)

public class Rectangle
{
    public double Width { get; set; }
    public double Height { get; set; }
    
    public double Area => Width * Height;
}

class Program
{
    static void Main()
    {
        // Create a Rectangle instance named rect with Width 5.0 and Height 3.0
        // Your code here
    }
}

Need a hint?

Use object initializer syntax: new Rectangle { Width = 5.0, Height = 3.0 }

4

Print the Area property of the Rectangle instance

In the Main method, add a Console.WriteLine statement to print the value of rect.Area.

C Sharp (C#)

public class Rectangle
{
    public double Width { get; set; }
    public double Height { get; set; }
    
    public double Area => Width * Height;
}

class Program
{
    static void Main()
    {
        Rectangle rect = new Rectangle { Width = 5.0, Height = 3.0 };
        // Print the area of rect
        // Your code here
    }
}

Need a hint?

Use Console.WriteLine(rect.Area); to display the area.