What is the main idea of the Set data structure in Dart and how does it work?

In Dart, the data structure Set represents a collection of unique elements without a specific order. The main idea is to store elements so that there are no duplicates, and to provide quick access, addition, and removal.

Set is implemented based on a hash table, which allows search and insertion operations to be performed in approximately constant time.

Example of using Set in Dart:

void main() {
  Set<String> fruits = {'apple', 'banana', 'orange'};
  fruits.add('banana'); // will not be added, as 'banana' already exists
  print(fruits); // {apple, banana, orange}
}

Thus, Set is convenient when you need to store unique elements and quickly check their presence.