Getting to Know Flutter: A Practical Way to Build Cross-Platform Apps

In modern application development, efficiency and release speed matter. In the past, building an app for Android and iOS meant maintaining separate codebases: Java or Kotlin for Android, and Objective-C or Swift for iOS. That approach required more time, budget, and engineering resources.

Flutter offers a modern approach that changes how we build applications.

What Is Flutter?

Flutter is an open-source UI toolkit developed by Google. It lets developers build high-quality applications for Android, iOS, web, Windows, macOS, and Linux from a single codebase.

Flutter uses Dart, a modern programming language designed to make it easier to create fast, structured, and responsive user interfaces.

Why Is Flutter So Popular?

There are several reasons developers and global companies such as BMW, Alibaba, and Google Pay rely on Flutter:

One Codebase for Multiple Platforms. Write the business logic and interface once, then run the app on different operating systems without rebuilding the core architecture.
Hot Reload for Faster Development. Stateful Hot Reload lets you see code changes on a simulator or physical device in seconds without losing the app's state or rebuilding from scratch.
"Everything is a Widget." In Flutter, almost every visual element is a widget—from text and buttons to padding and layouts such as Row and Column. This declarative approach makes interfaces modular, predictable, and easy to customize.
Near-Native Performance. Unlike WebView-based frameworks or JavaScript bridges, Flutter renders interfaces directly to the device's graphics canvas using modern engines such as Impeller. The result is smooth transitions and animations at up to 60–120 FPS.

Core Concepts for Beginners

If you are new to Flutter, two fundamental concepts form the basis of interface development:

1. StatelessWidget

A widget whose appearance stays the same after it is rendered. It works well for titles, icons, and layouts that display fixed information.

dart

class GreetingCard extends StatelessWidget {
  const GreetingCard({super.key});

  @override
  Widget build(BuildContext context) {
    return const Text(
      'Halo, Selamat Datang di Flutter!',
      style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
    );
  }
}

2. StatefulWidget

A widget whose appearance can change in response to user interaction or updated data (state). The setState() function tells Flutter to refresh the interface immediately.

dart

class CounterButton extends StatefulWidget {
  const CounterButton({super.key});

  @override
  State createState() => _CounterButtonState();
}

class _CounterButtonState extends State {
  int _counter = 0;

  void _tambah() {
    setState(() => _counter++);
  }

  @override
  Widget build(BuildContext context) {
    return ElevatedButton(
      onPressed: _tambah,
      child: Text('Diklik: $_counter kali'),
    );
  }
}

How Do You Get Started?

To start building with Flutter, you need three things:

Flutter SDK, available from the official flutter.dev website.
A code editor such as VS Code or Android Studio, with the Flutter and Dart extensions installed.
An emulator or simulator, or a physical phone connected by cable or wireless debugging.

Conclusion

Flutter is more than a trend. It is an efficient way to build fast, modern, and cost-effective cross-platform applications. Its learning curve is approachable, especially if you already understand the basics of object-oriented programming (OOP).

In the next article, we will walk through installing Flutter and creating your first Flutter app from scratch.