dart Getting started with dart

Remarks

Versions

Getters and Setters

void main() {
  var cat = new Cat();
  
  print("Is cat hungry? ${cat.isHungry}");  // Is cat hungry? true
  print("Is cat cuddly? ${cat.isCuddly}");  // Is cat cuddly? false
  print("Feed cat.");
  cat.isHungry = false;                     
  print("Is cat hungry? ${cat.isHungry}");  // Is cat hungry? false
  print("Is cat cuddly? ${cat.isCuddly}");  // Is cat cuddly? true
}

class Cat {
  bool _isHungry = true;
  
  bool get isCuddly => !_isHungry;
  
  bool get isHungry => _isHungry;
  bool set isHungry(bool hungry) => this._isHungry = hungry;
}
 

Dart class getters and setters allow APIs to encapsulate object state changes.

See dartpad example here: https://dartpad.dartlang.org/c25af60ca18a192b84af6990f3313233

Hello, World!

Create a new file named hello_world.dart with the following content:

void main() {
  print('Hello, World!');
}
 

In the terminal, navigate to the directory containing the file hello_world.dart and type the following:

dart hello_world.dart
 

Hit enter to display Hello, World! in the terminal window.

Http Request

Html

<img id="cats"></img>
 

Dart

import 'dart:html';

/// Stores the image in [blob] in the [ImageElement] of the given [selector].
void setImage(selector, blob) {
  FileReader reader = new FileReader();
  reader.onLoad.listen((fe) { 
    ImageElement image = document.querySelector(selector);
    image.src = reader.result;
  });
  reader.readAsDataUrl(blob);  
}

main() async {
  var url = "https://upload.wikimedia.org/wikipedia/commons/2/28/Tortoiseshell_she-cat.JPG";

  // Initiates a request and asynchronously waits for the result.
  var request = await HttpRequest.request(url, responseType: 'blob');
  var blob = request.response;
  setImage("#cats", blob);
}
 

Example

see Example on https://dartpad.dartlang.org/a0e092983f63a40b0b716989cac6969a

Installation or Setup

The Dart SDK includes everything you need to write and run Dart code: VM, libraries, analyzer, package manager, doc generator, formatter, debugger, and more. If you are doing web development, you will also need Dartium.

Automated installation and updates

• Installing Dart on Windows
• Installing Dart on Mac
• Installing Dart on Linux

Manual install

You can also manually install any version of the SDK.