I have confusion about Dart code in Flutter Framework - flutter

Question

import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: Text('My First App'),
),
body: Text('This is my default text'),
),
);
}
}
I have recently started learning the Flutter framework , and it's hell lot on confusing for me , can u please explain the sections of this code above like , what is that BuildContext
, the MaterialApp (is it a contructor or a class, ? ),
and it's parameters , I tried learning from their docs , but their is just too much its confusing to me , all i know from this code written in this class is that , build method returns a widget , and scaffold is some sort of predefined code which helps with the layout , something like bootstrap helps with CSS

Answer 1

Let's look at it one line at a time.
class MyApp extends StatelessWidget {
In this line you are declaring a class MyApp which extends the Stateless widget class. That means that MyApp will have the functionality of a Stateless widget and the bits of code that you are adding to it.
Widget build(BuildContext context) {
Here you are defining the build method. A Widget needs a build method, that's how flutter knows how to build the widget and show it. The build method receives a BuildContext parameter which is a handle to the location of a widget in the widget tree.
return MaterialApp(
The build method returns a MaterialApp widget. In fact, MaterialApp() is the constructor of the MaterialApp widget.
home: Scaffold(
appBar: AppBar(
title: Text('My First App'),
),
body: Text('This is my default text'),
The constructor of MaterialApp has a home and a body parameter. Here you are passing a Scaffold widget to the Home parameter. The Scaffold widget constructor (Scaffold()) has an appBar parameter, that receives a Widget (in this case, the Widget is AppBar). And the AppBar constructor has a title parameter, which receives a Text widget. And the body parameter also receives a Text widget.
),
);
}
}