C# Academy · Lesson

if/else, switch (classic), loops: for, while, do, foreach

Use if/else to branch, classic switch for discrete cases, and core loops (for, while, do, foreach) to repeat work clearly.

Lesson 1 of 38 steps

if/else, switch (classic), loops: for, while, do, foreach is a free C# Academy lesson on CoddyKit. This is lesson 1 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the C# Academy learning path, and your progress syncs across the web and the CoddyKit app. The C# Academy course includes 3 lessons in total.

Overview

Goal: Choose actions with if/else, map discrete cases with switch, and repeat work with for, while, do, and foreach.

if/else basics

Use if/else for simple, readable branching; keep conditions small.

using System;

public class Program
{
  public static void Main(string[] args)
  {
    int temperature = 18;

    if (temperature >= 25)
    {
      Console.WriteLine("Warm");
    }
    else if (temperature >= 15)
    {
      Console.WriteLine("Mild");
    }
    else
    {
      Console.WriteLine("Cold");
    }
  }
}

switch (classic)

switch selects one case; remember break to prevent falling into the next case.

using System;

public class Program
{
  public static void Main(string[] args)
  {
    int day = 3;

    switch (day)
    {
      case 1:
        Console.WriteLine("Mon");
        break;
      case 2:
        Console.WriteLine("Tue");
        break;
      case 3:
        Console.WriteLine("Wed");
        break;
      case 4:
        Console.WriteLine("Thu");
        break;
      case 5:
        Console.WriteLine("Fri");
        break;
      case 6:
      case 7:
        Console.WriteLine("Weekend");
        break;
      default:
        Console.WriteLine("Invalid");
        break;
    }
  }
}

for loop

for suits counted loops: init; condition; increment.

using System;

public class Program
{
  public static void Main(string[] args)
  {
    int sum = 0;
    for (int i = 1; i <= 5; i = i + 1)
    {
      sum = sum + i;
    }
    Console.WriteLine("Sum 1..5 = " + sum);
  }
}

while & do-while

while checks before; do checks after, so the body runs at least once.

using System;

public class Program
{
  public static void Main(string[] args)
  {
    // while: check before running
    int countdown = 3;
    while (countdown > 0)
    {
      Console.WriteLine(countdown);
      countdown = countdown - 1;
    }
    Console.WriteLine("Go!");

    // do-while: runs at least once
    int tries = 0;
    do
    {
      tries = tries + 1;
      Console.WriteLine("Attempt " + tries);
    } while (tries < 1);
  }
}

foreach basics

foreach loops over items in arrays and collections with clear, safe iteration.

using System;
using System.Collections.Generic;

public class Program
{
  public static void Main(string[] args)
  {
    int total = 0;
    int[] nums = new int[] { 2, 4, 6 };

    foreach (int n in nums)
    {
      total = total + n;
    }
    Console.WriteLine("Total = " + total);

    // Works with collections too
    List<string> names = new List<string>();
    names.Add("Ada");
    names.Add("Alan");
    foreach (string s in names)
    {
      Console.WriteLine("Hi " + s);
    }
  }
}

do-while fact

Quick check: Which statement about the do-while loop is correct?

Answer it in the interactive lesson

Recap

Recap: Pick if/else for simple branches, switch for discrete labels, and the right loop (for, while, do, foreach) for clear repetition.

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Frequently Asked Questions

Is the “if/else, switch (classic), loops: for, while, do, foreach” lesson free?

Yes — the full text of “if/else, switch (classic), loops: for, while, do, foreach” is free to read here on the web. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the C# Academy course, upgrade to CoddyKit PRO. The C# Academy course includes 3 lessons in total.

What will I learn in “if/else, switch (classic), loops: for, while, do, foreach”?

Use if/else to branch, classic switch for discrete cases, and core loops (for, while, do, foreach) to repeat work clearly. You practise C# Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start C# Academy?

No prior experience is required. C# Academy on CoddyKit is structured for beginners through advanced learners, so you can start here or from the beginning and move at your own pace. This is lesson 1 of 3.

How long does the “if/else, switch (classic), loops: for, while, do, foreach” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

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All lessons in this course

if/else, switch (classic), loops: for, while, do, foreach
break/continue; goto (avoid); scope; exceptions vs guard checks
Simple diagnostics: exceptions vs guard checks

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