Flutter named parameters attribute value

Question

I have a question i flutter in some named parameters like color: Or physics: in listviewbuilder the value is Colors.some color name in color and Neverscroll in physics My question is how to know that the attribute take this value although I tried to search in source code in flutter but i couldn't find out how Thanks a lot

Answer 1

Theses are known as named constructor. Check this class

class MyClass {
  final int a;
  final String b;
  final double c;

  MyClass({required this.a, required this.b, this.c = 1.0});
}

Once you like to use this class you need to provide data like

MyClass(a: 1, b: "");

Note here a and b are required but c is using default value. Also, you can make nullable variables.

A good start guide will be language-tour