--- title: Switch Case --- # Switch Case Switch is a selection statement that chooses a switch case section depending on the value matched with the expression/value being evaluated.1 If none of the case statements match the value of the switched variable, the default path is chosen. The switch statement is like a set of `if statements`. We exit from the switch by `break`. ## Example ``` public enum Colors { Red, Blue, Green, Orange } Colors myColor; ... myColor is set to one of the enum values ... switch(myColor){ case Colors.Red: Console.WriteLine("How you like them apples?"); break; case Colors.Blue: Console.WriteLine("Ice Ice Baby..."); break; case Colors.Green: Console.WriteLine("Fore!"); break; default: Console.WriteLine("I have a hard time when I try to rhyme."); } ``` ## Output ``` If myColor is Colors.Red: > How you like them apples? If myColor is Colors.Blue: > Ice Ice Baby... If myColor is Colors.Green: > Fore! If myColor is Colors.Orange: > I have a hard time when I try to rhyme. ``` ## Fallthrough It is also possible to use multiple statements produce the same outcome, by letting the cases 'fallthrough', like so: ``` switch(myColor) { case Colors.Red: case Colors.Blue: //Code break; ... } ``` This will execute the same lines of code if myColor is either Red or Blue. ## When clause Starting with C# 7.0 you can use `when` clause to specify additional condition that must be satisfied. When clause is optional and is used right after specific case. ```csharp Dog dog = new Dog { Name = "Charlie", Breed = "Affenpinscher", Age = 3 }; switch (dog) { case Dog d when d.Breed == "Affenpinscher" && d.Age >= 6: Console.WriteLine($"{dog.Name} is considered a senior dog."); break; case Dog d when d.Breed == "Affenpinscher" && d.Age >= 2: Console.WriteLine($"{dog.Name} is considered an adult dog."); break; case Dog d when d.Breed == "Affenpinscher": Console.WriteLine($"{dog.Name} is considered a puppy."); break; case Dog d when d.Breed == "Chihuahua" && d.Age >= 4: Console.WriteLine($"{dog.Name} is considered a senior dog."); break; case Dog d when d.Breed == "Chihuahua" && d.Age >= 2: Console.WriteLine($"{dog.Name} is considered an adult dog."); break; case Dog d when d.Breed == "Chihuahua": Console.WriteLine($"{dog.Name} is considered a puppy."); break; default: Console.WriteLine($"We have no information according {dog.Breed} breed."); break; } ``` As you see in the above example after `when` keyword you should specify logical condition (an instruction that returns bool value). ### Sources: - 1 https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/switch