對 Dart 的感想

感覺 Dart 介乎 JavaScript 和 Java 之間

對比 Java

void main() {
  var person = new Person();
  person.firstName = 'Jason';
  person.printName();
}

class Person {
  String firstName;

  Person(name) {
    firstName = name;
  }

  printName() {
    print(firstName);
  }
}

和 Java 相似:

class
```
class Person
```
constructor
```
Person(name)
```

和 Java 不同:

語化對比 Java 有所簡化, 沒有 public, protected, private. If an identifier starts with an underscore (_), it’s private to its library. For details, see Libraries and visibility.
一個 dart file 可以有不同 public class, simplify file structure

對比 JavaScript

class Deck {
  List<Card> cards = [];

  Deck() {
    var ranks = ['Ace', 'Two', 'Three', 'Four'];
    var suits = ['Diamonds', 'Hearts'];

    for (var suit in suits) {
      for (var rank in ranks) {
        var card = new Card(suit: suit, rank: rank);
        cards.add(card);
      }
    }
  }

  toString() {
    return cards.toString();
  }

  shuffle() {
    cards.shuffle();
  }

  cardsWithSuit(String suit) {
    return cards.where((card) => card.suit == suit);
  }

  deal(int size) {
    var hand = cards.sublist(0, size);
    cards = cards.sublist(size);
    return hand;
  }

  removeCard(String suit, String rank) {
    cards.removeWhere((card) => (card.suit == suit) && (card.rank == rank));
  }
}

class Card {
  String suit;
  String rank;

  Card({this.suit, this.rank});

  toString() {
    return "$rank of ${suit}";
  }
}

和 JavaScript 相似:

Simple syntax & expression

var ranks = ['Ace', 'Two', 'Three', 'Four'];

String template
```
return "$rank of ${suit}";
```

Arrow function

cards.removeWhere((card) => (card.suit == suit) && (card.rank == rank));

和 JavaScript 不同:

Named constructor
```
Card({this.suit, this.rank});
```
有 Standard library
有 Strong type, 但有 type inference
有 Generic

其他特點

內置格式化工具 dmf