State Management Development Tutorials, Guides & Insights

A closure is a function that "remembers" the environment in which it was created. In JavaScript, closures are created every time a function is created. A closure gives you access to the outer function’s scope from an inner function. In other words, a closure is a combination of a function and the lexical environment within which that function was declared.

Closures are essential because they enable powerful and flexible programming techniques. They allow you to:

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class Weather {
  final String cityName;
  final double temperature;
  final String description;
  final String icon;

  Weather({
    required this.cityName,
    required this.temperature,
    required this.description,
    required this.icon,
  });

  factory Weather.fromJson(Map<String, dynamic> json) {
    return Weather(
      cityName: json['name'],
      temperature: json['main']['temp'].toDouble(),
      description: json['weather'][0]['description'],
      icon: json['weather'][0]['icon'],
    );
  }
}

Create a new file lib/services/weather_service.dart to handle API requests:

Replace the content of lib/main.dart with the following code:

import 'package:flutter/material.dart';

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

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

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

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

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter Counter'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

In this tutorial, we will learn how to build a modern web application using React and Redux. React is a popular JavaScript library for building user interfaces, while Redux is a predictable state container that helps manage application state. We'll cover the basics of setting up a React project, integrating Redux, and implementing a simple application to demonstrate these tools.

Before starting this tutorial, you should have a basic understanding of JavaScript and familiarity with the command line. Additionally, ensure you have Node.js and npm (Node Package Manager) installed on your machine.