Switch Statement

When you're checking a single value against a bunch of possible matches, a long if-else if chain gets noisy. Enter switch — cleaner, more readable, and built exactly for this job.

Basic switch

You hand switch a value. It jumps to the case that matches. Each case needs a break to stop it from falling through to the next.

using System;

class Program {
  static void Main() {
    int day = 3;
    switch (day) {
      case 1:
        Console.WriteLine("Monday");
        break;
      case 2:
        Console.WriteLine("Tuesday");
        break;
      case 3:
        Console.WriteLine("Wednesday");
        break;
      case 4:
        Console.WriteLine("Thursday");
        break;
      case 5:
        Console.WriteLine("Friday");
        break;
      default:
        Console.WriteLine("Weekend!");
        break;
    }
  }
}
    

Pattern Matching with switch

C# modernized switch with pattern matching. You can match types, ranges, and even add conditions with when.

using System;

class Program {
  static void Main() {
    object value = 42;
    switch (value) {
      case int i when i > 0:
        Console.WriteLine("Positive integer: " + i);
        break;
      case string s:
        Console.WriteLine("String: " + s);
        break;
      case null:
        Console.WriteLine("It's null");
        break;
      default:
        Console.WriteLine("Something else");
        break;
    }
  }
}
    

fall-through Behavior

Unlike C or C++, C# requires a break (or return, goto) at the end of each case. Accidental fall-through is a compile error — the compiler has your back.

using System;

class Program {
  static void Main() {
    char grade = 'B';
    switch (grade) {
      case 'A':
        Console.WriteLine("Excellent!");
        break;
      case 'B':
      case 'C':
        Console.WriteLine("Good effort");
        break;
      case 'D':
        Console.WriteLine("Needs improvement");
        break;
      default:
        Console.WriteLine("Invalid grade");
        break;
    }
  }
}
    

switch Expression

C# 8.0 introduced switch expressions — a compact, functional style that returns a value directly without all the case/break ceremony.

using System;

class Program {
  static void Main() {
    int day = 3;
    string name = day switch {
      1 => "Monday",
      2 => "Tuesday",
      3 => "Wednesday",
      4 => "Thursday",
      5 => "Friday",
      _ => "Weekend"
    };
    Console.WriteLine(name);
  }
}