Writing Dart in DartPad

A guide to writing and running Dart code in a browser-based editor—no setup required.

Getting Started with Dart

DartPad provides a browser-based environment for experimenting with the Dart language and developing applications for the web or mobile (via Flutter). To start writing Dart in DartPad:

Open DartPad.
Write a main() function as the entry point.
Use the editor for real-time feedback and auto-completion.
Press Ctrl+Enter to run the code and see the output.

Tip: Use the 'Save' feature to retain your work.

Dart in Action

DartPad allows you to write Dart apps for the web and Flutter. Here's an example of a simple Dart program:

void main() {
  print('Hello from DartPad!');
  int age = 30;
  String message = age > 18 ? 'Adult' : 'Minor';
  print(message);
}

You can also run Flutter apps in DartPad. Here’s a simple Flutter application snippet:

import 'package:flutter/material.dart';

void main() {
  runApp(MaterialApp(
    title: 'Hello Flutter',
    home: Scaffold(
      appBar: AppBar(title: const Text('Hello World')),
      body: const Center(
        child: Text('Hello from Flutter!'),
      ),
    ),
  ));
}

Click 'Run' to preview the Flutter UI and make changes directly in the browser.

Advanced Tips

1. Asynchronous Programming

Use async and await for asynchronous Dart. Here's a simple example:

Future<String> fetchData() async {
  await Future.delayed(const Duration(seconds: 1));
  return 'Data fetched!';
}

void main() async {
  final result = await fetchData();
  print(result);
}

2. Error Handling

Dart supports try/catch blocks for robust handling of errors in both synchronous and asynchronous code:

void main() {
  try {
    int a = 10 ~/ 0;
  } catch (e) {
    print('Caught error: $e');
  }
}

Sharing and Collaborating

After writing Dart code in DartPad, use the 'Share' feature to collaborate with others. You can:

Generate a public URL for the code.
Save your code to your account for future access.
Embed code examples using iframes for educational purposes.

Share your code by clicking the 'Share' button and copying the generated link. DartPad supports collaboration and real-time sharing seamlessly.

Next Steps

Explore other guides and examples to learn how to:

Need help? Contact us, view FAQs, or dive into our documentation to master Dart writing in DartPad!