Is there a better alternative than this to 'switch on type'?

Question

Seeing as C# can't switch on a Type (which I gather wasn't added as a special case because is relationships mean that more than one distinct case might apply), is there a better way to simulate switching on type other than this?

void Foo(object o) {     if (o is A)     {         ((A)o).Hop();     }     else if (o is B)     {         ((B)o).Skip();     }     else     {         throw new ArgumentException("Unexpected type: " + o.GetType());     } } 

Answer 1

With C# 7, which shipped with Visual Studio 2017 (Release 15.*), you are able to use Types in case statements (pattern matching):

switch(shape) {     case Circle c:         WriteLine($"circle with radius {c.Radius}");         break;     case Rectangle s when (s.Length == s.Height):         WriteLine($"{s.Length} x {s.Height} square");         break;     case Rectangle r:         WriteLine($"{r.Length} x {r.Height} rectangle");         break;     default:         WriteLine("<unknown shape>");         break;     case null:         throw new ArgumentNullException(nameof(shape)); } 

With C# 6, you can use a switch statement with the nameof() operator (thanks @Joey Adams):

switch(o.GetType().Name) {     case nameof(AType):         break;     case nameof(BType):         break; } 

With C# 5 and earlier, you could use a switch statement, but you'll have to use a magic string containing the type name... which is not particularly refactor friendly (thanks @nukefusion)

switch(o.GetType().Name) {   case "AType":     break; }