C# Practice Exercises

Pattern Matching Classifier

Classify mixed values with property and relational patterns.

Introduction

Modern C# patterns keep type extraction and validation in one expression.

The string property pattern checks Length after confirming the runtime type.

Runnable C# example

Program.cs

using System;
class Program
{
    static string Classify(object? value) => value switch
    {
        int and >= 18 => "adult age", string { Length: 0 } => "empty text",
        string text => $"text({text.Length})", null => "null", _ => "other"
    };
    static void Main() => Console.WriteLine(Classify("CSharp"));
}

Result of running the code

text(6)

Practice with the debugger

Set a breakpoint on an important assignment or condition, click Debug, and inspect the local values before stepping to the next line.

Practice with a challenge

Use what this lesson covers to solve a real problem. Each challenge runs in your browser with instant tests and an AI review.

Triangle Classification Classify three side lengths as invalid, equilateral, isosceles, or scalene. Easy

All challenges