Page 19 - Dart Language

Types for the key and value can also be defined using generics:

var nobleGases = new Map<int, String>();
var nobleGases = <int, String>{};

Maps can otherwise be created using the map literal:

var map = {
"key1": "value1",
"key2": "value2"
};

Map each element in the collection.

All collection objects contain a map method that takes a Function as an argument, which must take
a single argument. This returns an Iterable backed by the collection. When the Iterable is
iterated, each step calls the function with a new element of the collection, and the result of the call
becomes the next element of the iteration.

You can turn an Iterable into a collection again by using the Iterable.toSet() or Iterable.toList()
methods, or by using a collection constructor which takes an iterable like Queue.from or List.from.

Example:

main() {
var cats = [
'Abyssinian',
'Scottish Fold',
'Domestic Shorthair'
];

print(cats); // [Abyssinian, Scottish Fold, Domestic Shorthair]

var catsInReverse =
cats.map((String cat) {
return new String.fromCharCodes(cat.codeUnits.reversed);
})
.toList(); // [nainissybA, dloF hsittocS, riahtrohS citsemoD]

print(catsInReverse);
}

See dartpad example here: https://dartpad.dartlang.org/a18367ff767f172b34ff03c7008a6fa1

Filter a list

Dart allows to easily filter a list using where.

var fruits = ['apples', 'oranges', 'bananas'];
fruits.where((f) => f.startsWith('a')).toList(); //apples

Of course you can use some AND or OR operators in your where clause.

https://riptutorial.com/ 14