Collections

Lists

// ordered group of objects
var list = [1, 2, 3];

print(list.length); //Print: 3
print(list[1]); //Print: 2

// other ways of list declaration and initializations

List<String> cities = <String>["New York", "Mumbai", "Tokyo"];

// To create a list that’s a compile-time constant
const constantCities = const ["New York", "Mumbai", "Tokyo"];

Sets

// A set in Dart is an unordered collection of unique items.
var halogens = {'fluorine', 'chlorine', 'bromine', 'iodine', 'astatine'};

// to create an empty set
var names = <String>{};
Set<String> names = {}; // This works, too.
//var names = {}; // Creates a map, not a set.

Maps

// a map is an object that associates keys and values
var person = Map<String, String>();
// To initialize the map, do this:

person['lastName'] = 'Tesla';

print(person); //Print: {firstName: Nicola, lastName: Tesla}
print(person['lastName']); //Print: Tesla


var nobleGases = {
  // Key: Value
  2: 'helium',
  10: 'neon',
  18: 'argon',
};

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