Flutter for Beginners

Callable classes

In the same way that Dart functions are nothing more than objects, Dart classes can behave like functions too, that is, they can be invoked, take some arguments, and return something as a result. The syntax for emulating a function in a class is as follows:

class ShouldWriteAProgram { // this is simple class   String language;  String platform;  ShouldWriteAProgram(this.language, this.platform);  // this special method named 'call' makes the class behave as a function  bool call(String category) {    if(language == "Dart" && platform == "Flutter") {      return category != "to-do";    }     return false;  } }main() {  var shouldWrite = ShouldWriteAProgram("Dart", "Flutter");  print(shouldWrite("todo")); // prints false. // this function is invoking ...