Pattern matching in switch in C Sharp (C#) - Mini Project: Build & Apply

Pattern matching in switch

📖 Scenario: You are building a simple program that identifies the type of a shape based on its properties. This is like sorting different objects by looking at their features.

🎯 Goal: Create a program that uses switch with pattern matching to identify shapes by their properties.

📋 What You'll Learn

Create a variable called shape with a value representing a shape object.

Create a variable called description to hold the shape description.

Use a switch expression with pattern matching on shape.

Print the description to the console.

💡 Why This Matters

🌍 Real World

Pattern matching helps you write clear code that decides actions based on object properties, like sorting shapes or handling different user inputs.

💼 Career

Understanding pattern matching in switch statements is useful for writing clean, readable code in C# applications, especially in UI, data processing, and game development.

1

Create the shape variable

Create a variable called shape and assign it the value new { Sides = 3, Name = "Triangle" }.

C Sharp (C#)

# Create a variable called shape with Sides = 3 and Name = "Triangle"
// Your code here

Need a hint?

Use var shape = new { Sides = 3, Name = "Triangle" }; to create an anonymous object.

2

Create the description variable

Create a variable called description and set it to an empty string "".

C Sharp (C#)

var shape = new { Sides = 3, Name = "Triangle" };
// Create a variable called description and set it to ""
// Your code here

Need a hint?

Use string description = ""; to create an empty string variable.

3

Use switch with pattern matching

Use a switch expression on shape to set description as follows:
- If shape.Sides is 3, set description to "Triangle".
- If shape.Sides is 4, set description to "Quadrilateral".
- Otherwise, set description to "Unknown shape".

C Sharp (C#)

var shape = new { Sides = 3, Name = "Triangle" };
string description = "";
// Use switch expression with pattern matching on shape to set description
// Your code here

Need a hint?

Use switch with pattern matching like shape switch { { Sides: 3 } => "Triangle", ... }.

4

Print the description

Write a Console.WriteLine statement to print the description variable.

C Sharp (C#)

var shape = new { Sides = 3, Name = "Triangle" };
string description = shape switch
{
    { Sides: 3 } => "Triangle",
    { Sides: 4 } => "Quadrilateral",
    _ => "Unknown shape"
};
// Print the description variable
// Your code here

Need a hint?

Use Console.WriteLine(description); to print the result.