Nested If + Else If Ladder

int age = 20;
bool hasID = true;

if (age >= 18) {
    if (hasID) {
        Console.WriteLine("Entry allowed");
    } else {
        Console.WriteLine("ID required");
    }
} else if (age >= 16) {
    Console.WriteLine("Entry with guardian");
} else {
    Console.WriteLine("Not allowed");
}

Switch: Cleaner Than 10 If-Else

string role = "admin";
switch (role) {
    case "admin":
        Console.WriteLine("Full access");
        break;
    case "editor":
        Console.WriteLine("Can edit");
        break;
    case "user":
    case "guest": // Fall-through: both run same code
        Console.WriteLine("Read only");
        break;
    default:
        Console.WriteLine("Unknown role");
        break;
}

Pattern Matching Switch - C# 8+

int marks = 85;
string grade = marks switch {
    >= 90 => "A",
    >= 75 => "B", 
    >= 60 => "C",
    _ => "Fail" // _ is default
};