counter money app

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(primarySwatch: Colors.yellow),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int number = 0;

  void increment() {
    setState(() => number++);
  }

  void decrement() {
    setState(() => number--);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Counter App'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              'This is how much money I have:',
              style: TextStyle(fontSize: 20),
            ),
            Text(
              '\$$number',
              style: TextStyle(fontSize: 130),
            ),
          ],
        ),
      ),
      floatingActionButton: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          FloatingActionButton(
            onPressed: increment,
            child: Icon(Icons.add),
          ),
          SizedBox(width: 10),
          FloatingActionButton(
            onPressed: decrement,
            child: Icon(Icons.remove),
          ),
        ],
      ),
    );
  }
}