Question

How do I delete duplicates from a list without fooling around with a set? Is there something like list.distinct()? or list.unique()?

void main() {
  print("Hello, World!");

  List<String> list = ['abc',"abc",'def'];
  list.forEach((f) => print("this is list $f"));

  Set<String> set = new Set<String>.from(list);
  print("this is #0 ${list[0]}");
  set.forEach((f) => print("set: $f"));

  List<String> l2= new List<String>.from(set);
  l2.forEach((f) => print("This is new $f"));
}

Hello, World!
this is list abc
this is list abc
this is list def
this is #0 abc
set: abc
set: def
This is new abc
This is new def

---

Set seems to be way faster!! But it loses the order of the items :/

Answer 1

I have a library called Reactive-Dart that contains many composable operators for terminating and non-terminating sequences. For your scenario it would look something like this:

final newList = [];
Observable
   .fromList(['abc', 'abc', 'def'])
   .distinct()
   .observe((next) => newList.add(next), () => print(newList));

Yielding:

[abc, def]

I should add that there are other libraries out there with similar features. Check around on GitHub and I’m sure you’ll find something suitable.