C# – using the ‘is’ keyword in a switch in c#


I'm currently adding some new extended classes to this code:

foreach (BaseType b in CollectionOfExtendedTypes) {
  if (b is ExtendedType1) {
    ((ExtendedType1) b).foo = this;

  else if (b is ExtendedType2) {
    ((ExtenedType2) b).foo = this;

  else {
    b.foo = this;


and was curious if there is a way to use the is keyword functionality in a switch statement?

Best Solution

The latest version of C# (7) now includes this functionality

Type pattern

The type pattern enables concise type evaluation and conversion. When used with the switch statement to perform pattern matching, it tests whether an expression can be converted to a specified type and, if it can be, casts it to a variable of that type. Its syntax is:

   case type varname