Dart List

list.dart

void main() {
  List<String> usernames = ['lana', 'del', 'rey', 'hope', 'sandoval'];
  
  // add => bottom
  usernames.add('nikk');
  print(usernames); //[lana, del, rey, hope, sandoval, nikk]
  
  // add all
  usernames.addAll(['wenyan', 'li']);
  print(usernames); // [lana, del, rey, hope, sandoval, nikk, wenyan, li]
  
  // remove at
  usernames.removeAt(0);
  print(usernames); // [del, rey, hope, sandoval, nikk, wenyan, li]
  
  // remove with condition
  usernames.removeWhere((x) => x.contains('an'));
  print(usernames); // [del, rey, hope, nikk, li]
  
  // add => specificed position
  usernames.insert(3, 'tony');
  print(usernames); // [del, rey, hope, tony, nikk, li]
  
  // any
  bool hasDeGuy = usernames.any((x) => x.startsWith(new RegExp(r'(de)')));
  print(hasDeGuy); // true
  
  // where (filter)
  var filtered = usernames.where((x) => x.startsWith(new RegExp(r'(de|re|ho|to)')));
  print(filtered); // [del, rey, hope, tony]
  
  // iteration
  var handled = filtered.map((original) {
    return original + '_handled';
  });
  print(handled); // [del_handled, rey_handled, hope_handled, tony_handled]
  
  // every 
  print(handled.every((h) => h.contains('_handled'))); // true
  
  // fold (reduce)
  var folded = handled.fold('user_names:', (prev, item) {
    return prev + item.replaceAll('handled', '');
  });
  print(folded); // user_names:del_rey_hope_tony_
  
  // forEach
  handled.forEach((item) => {
    print(item)
  });
  // del_handled
  // rey_handled
  // hope_handled
  // tony_handled
}