3.11. Dart Basics: Flutter Basics

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To start building applications from scratch to advanced using Flutter and Dart, it is essential to have a solid understanding of the basic concepts of these two technologies. In this text, we'll cover the basics of Dart and Flutter.

Basic Dart Concepts

Dart is an object-oriented programming language that was developed by Google. It is used to build mobile, web, and server applications. Dart is the programming language used to code Flutter apps.

Dart basics include:

Variables and Data Types

In Dart, variables store references to values. You can use the 'var' command to declare a variable. Dart has data types like 'int', 'double', 'String', 'bool' and 'dynamic'.

Operators

Dart supports a variety of operators, such as arithmetic operators (+, -, *, /, %, ++, --), equality and relational operators (==, !=, >, <, >=, <=), logical operators (&&, ||, !) and others.

Flow Control

Dart uses common flow control structures like 'if', 'else', 'for', 'while', 'do-while', 'switch' and 'break' to control program flow.

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Functions

Functions in Dart are blocks of code that perform a specific task. You can define a function using the keyword 'void' followed by the name of the function.

Collections

Dart supports collections such as Lists, Sets, and Maps. They are used to store and manipulate a group of objects.

Classes and Objects

Dart is an object-oriented programming language, which means that it uses classes and objects. A class is a template for creating objects, and an object is an instance of a class.

Fundamentals of Flutter

Flutter is a framework developed by Google to create mobile apps for iOS and Android from a single codebase. It uses the Dart language and provides a rich collection of pre-built widgets.

Flutter basics include:

Widgets

In Flutter, everything is a widget. Widgets are the basic building blocks of a Flutter app. They describe how the user interface should appear.

Widget Tree

Widgets in Flutter are organized in a hierarchical tree. The widget tree consists of a root widget from which all other widgets derive.

State

In Flutter, widgets can be either immutable (stateless) or mutable (stateful). A stateless widget is described by its properties, which are immutable, whereas a stateful widget can change over time.

Hot Reload

Flutter has a feature called 'hot reload' that allows developers to see changes made to code almost instantly without losing application state.

Layout

Flutter provides a variety of widgets to help create layouts, including widgets for rows, columns, grids, lists, stacks, cards, etc.

Understanding these Dart and Flutter basics is crucial for building applications from scratch to advanced. Once you have a good understanding of these concepts, you can move on to more advanced topics and start building your own apps with Flutter and Dart.

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303.12. Dart Basics: Widgets and Layout