C# Programming Tutorial
Lesson 5 of 23 22% of course

Control Flow: if, switch, loops

2 · 5 min · 5/23/2026

Learn Control Flow: if, switch, loops in our free C# Programming Tutorial series. Step-by-step explanations, examples, and interview tips on Toolliyo Academy.

Sign in to track progress and bookmarks.

Control Flow: if, switch, loops — C# Programming Tutorial
Advanced track — C# / .NET

Advanced Control Flow: if, switch, loops in C# Programming Tutorial. Deep dive with production-oriented examples—not a shallow overview.

Architecture & mental model

This lesson covers Control Flow: if, switch, loops at an intermediate-to-advanced level within C# Basics. You will connect C# / .NET concepts to production constraints: performance, security, testability, and operability.

Advanced learners should already know syntax basics; here we focus on why teams choose specific patterns and how they fail in real systems.

Implementation (production-style)

Type the code below; change names and types to match your domain. Compare with how C# / .NET teams structure layers in mature codebases.

// Control Flow: if, switch, loops — C# Programming Tutorial
public sealed class ControlFlowifswitchloops
{
    private readonly ILogger _log;

    public ControlFlowifswitchloops(ILogger log)
        => _log = log;

    public async Task ExecuteAsync(CancellationToken ct = default)
    {
        _log.LogInformation("Applying concept: Control Flow: if, switch, loops");
        await Task.CompletedTask;
    }
}

Decision checklist

  • Requirements: What are latency, consistency, and security needs for "Control Flow: if, switch, loops"?
  • Boundaries: Which layer owns this logic (UI, API, domain, infrastructure)?
  • Failure modes: What happens when dependencies time out or return partial data?
  • Observability: What logs or metrics prove this feature works in production?

Hands-on lab (45–60 min)

  1. Reproduce the primary example for "Control Flow: if, switch, loops" in a scratch project using C# / .NET.
  2. Add one automated test (unit or integration) that would fail if you break the core behavior.
  3. Introduce a deliberate bug (wrong lifetime, missing await, wrong dependency order) and observe the symptom.
  4. Document one trade-off you would present in a design review.

Pitfalls senior engineers avoid

  • Treating tutorial demos as production architecture without hardening.
  • Skipping observability (logs, metrics, traces) when adding complexity.
  • Optimizing before measuring bottlenecks.
  • Ignoring team conventions and existing codebase patterns.

Interview depth

Question: Explain Control Flow: if, switch, loops to a junior developer in 2 minutes, then list two trade-offs.

Strong answer: Start with the problem it solves, describe one real project usage, mention a failure you debugged or would test for, and close with alternatives (when not to use this approach).

Next level

Pair this lesson with official docs for C# / .NET, then read source or decompile one framework call path involved in "Control Flow: if, switch, loops". Advanced mastery comes from combining reading, debugging, and shipping.

Summary

You completed an advanced treatment of Control Flow: if, switch, loops. Revisit after building a feature that uses it end-to-end; spaced repetition with real code beats re-reading alone.

Test your knowledge

Quizzes linked to this course—pass to earn certificates.

Browse all quizzes
C# Programming Tutorial

On this page

Architecture & mental model Implementation (production-style) Decision checklist Hands-on lab (45–60 min) Pitfalls senior engineers avoid Interview depth Summary
C# Basics
Introduction to C# and .NET C# Environment Setup (SDK, VS Code, Visual Studio) Variables, Data Types, and Literals Operators and Expressions Control Flow: if, switch, loops Arrays and Strings in C#
Object-Oriented Programming
Classes and Objects Constructors and Destructors Inheritance and Polymorphism Interfaces and Abstract Classes Encapsulation and Access Modifiers Static Members and Sealed Classes
Advanced C#
Exception Handling (try/catch/finally) Generics and Constraints Delegates and Events Lambda Expressions and LINQ Introduction Async and Await in C# File I/O and Serialization Records, Pattern Matching, and Nullable Reference Types Memory, Span<T>, and Performance Tuning in C#
Interview Preparation
Top C# Interview Questions (Junior to Mid) Value Type vs Reference Type Deep Dive C# Coding Challenges for Practice