Use symbols to pass a class member's name?-CodePudding

I'm writing a testing utility function and would like to pass a class member name and get its value. Could I use Symbols for this? My test code looks like this

class Foo {
  String a = 'A';
  String b = 'B';
  static void output(Symbol symbol) {
    debugPrint("The value is '$symbol'");
  }
}

Foo.output(#a);

I'm trying to get a result like The value is 'A' but I'm getting The value is 'Symbol("a")'?

CodePudding user response：

Getting the value of something by name, where the name is a value, and at runtime, that is reflection. You need dart:mirrors for that, which isn't available on most platforms.

Better yet, don't do it at all. Dart has first class functions, so you can pass in a function accessing the variable instead:

class Foo {
  String a = 'A';
  String b = 'B';
  static void output(String read(Foo value)) {
    debugPrint("The value is '${read(this)}'");
  }
}

void main() {
  var foo = Foo();
  foo.output((f) => f.a);
  foo.output((f) => f.b);
}