Example showing how to update a list

update_list.dart

class Person {
  Person(this.name);
  
  final String name;
  
  String toString() => name;
}

void main() {
  final items = [Person("juan"), Person("pedro"), Person("coso")];
  
  print("before update:");
  print(items);
  
  final index = items.indexWhere((p) => p.name == 'pedro');
  if (index != -1) {
    items[index] = Person("otro");
  }
  
  print("after update:");
  print(items);
}