Navigator.push() & Navigator.pop()

//step1
import 'package:flutter/material.dart';

//step2
void main() => runApp(MyApp());

//step3
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      home: MyHomePage(),
    );
  }
}

//step4
class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}


//step5
class MySecondPage extends StatefulWidget {
  @override
  _MySecondPageState createState() => _MySecondPageState();
}

//step6
class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Home - TutorialKart'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Go to Second Screen'),
          onPressed: () {
            Navigator.push(
              context,
              MaterialPageRoute(builder: (context) => MySecondPage()),
            );
          },
        ),
      ),
    );
  }
}


//step7
class _MySecondPageState extends State<MySecondPage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Second Screen'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Go back to Home Screen'),
          onPressed: () {
            Navigator.pop(context);
          },
        ),
      ),
    );
  }
}


                      

1. define StatefulWidget 'MyHomePage' & 'MySecondPage' (step4 & step5)

2. define state class '_MyHomePageState' & '_MySecondPageState' for 'MyHomePage' & 'MySecondPage' (step6 & step7)

3. inject StatefulWidget 'MyHomePage' & 'MySecondPage' into state class '_MyHomePageState' & '_MySecondPageState'

4. define appBar and body for each page

5. call MyHomePage() in main() (step3)