Dart runtimeType checking in switch statement

If you want to do flow control based on object's type, you actually want to do it based on whether an object's class implements an interface, not what it's run time type is. This is what the Type Test Operators is and is! are for.

Remember that in Dart a class is also an interface, so you can test if an object is a specific class.

class Something { ...}var s = new Something();print(s is Something);     // true

Note that things we tend to think of as 'classes' such as List an Map, are not classes, they are interfaces. Anything that returns a instance of such (including constructors) in fact returns a class that implements the interface.

You can use generics, but be careful.

void main() {  var a = [1, 2, 'three'];  print(a is List);          // True  print(a is List<int>);     // True!!!!  print(a is List<String>);  // True!!!!  var b = new List<int>.from([1, 2, 3]);  print(b is List);          // True  print(b is List<int>);     // True  print(b is List<String>);  // False}

A class can implement an interface via explicitly implementing it, inheriting from a class that implements it, or through a mix-in.

class Base {  void a() {}}class Mix {  void b() {}}class Mixed extends Base with Mix {} class Explicit implements Base {  void a() {}  }void main() {  var c = new Mixed();  print(c is Mixed);         // True  print(c is Base);          // True  print(c is Mix);           // True  var d = new Explicit();  print(d is Base);          // True}