Lesson 3 of 40 Foundations Beginner ⏱ 25 min

Control Flow — if, switch, loops

Control how your program makes decisions and repeats work with if/else, switch expressions, for, foreach, while, and the new C# pattern-matching switch.

Part 1: if / else if / else

int score = 85;
if (score >= 90)
    Console.WriteLine("Grade: A");
else if (score >= 80)
    Console.WriteLine("Grade: B");
else
    Console.WriteLine("Grade: C or below");

Part 2: Switch Expressions (Modern C#)

string grade = score switch
{
    >= 90 => "A",
    >= 80 => "B",
    >= 70 => "C",
    >= 60 => "D",
    _ => "F"
};

The discard pattern _ acts as the default case. Switch expressions are exhaustive — the compiler warns if you miss a case.

Part 3: Loops — for, foreach, while

// for loop
for (int i = 0; i < 5; i++)
Console.Write($"{i} ");

// foreach (preferred for collections)
var names = new[] {"Alice","Bob","Carol"};
foreach (var name in names)
Console.WriteLine(name);

// while loop
int n = 1;
while (n <= 5) { Console.Write(n++ + " "); }

Part 4: break, continue & goto (avoid)

foreach (var item in items)
{
    if (item.IsDeleted) continue; // Skip to next
    if (item.IsError) break; // Exit loop entirely
    Process(item);
}

// goto — avoid in modern C#
// Use structured control flow instead

Control Flow — if, switch, loops

Part 1: if / else if / else

Part 2: Switch Expressions (Modern C#)

Part 3: Loops — for, foreach, while

Part 4: break, continue & goto (avoid)

C# in Visual Studio 2026