StatefulWidget Counter App

 import "package:flutter/material.dart";

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

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

  @override
  Widget build(BuildContext context)
  {
    return MaterialApp(
      title: "Hello",
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.indigo,
      ),
      home: const FlutterApp(),
      /*"home" decide that which screen will open first.starting Launcher screen will decide from here*/
    );
  }
}

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

/*Here "State" is the class of "StatefulWidget" type."createState()" is the required function in the StatefulWidget.
createState() function required State of class type "State" object*/
  @override
  State<StatefulWidget> createState() {
    return FlutterState();
  }
}
/*State<StatefulWidget> createState() => FlutterState();*/
/*This is the another way for denoting the single line return statement using "=>"*/


class FlutterState extends State<FlutterApp>
{
  var count = 0;
  @override
  Widget build(BuildContext context)
  {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Hello Flutter"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text("Counter: $count", style: const TextStyle(fontSize: 34),),
            ElevatedButton(
              onPressed: (){
                setState((){
                  //count = count + 1; //This is the first way for counter
                  //count += 1;
                  count++;
                  print(count);
                },);
              },
              child: const Text("Click Here!"),
            ),

            /* ElevatedButton(
              onPressed: (){
                count++;          *//*This is the Second way for counter*//*
                setState((){ },);
                print(count);
              },
              child: const Text("Click!"),
            ),*/
          ],
        ),
      ),
    );
  }
}