3. Basic Dart Concepts

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Dart is a programming language developed by Google that is used to build mobile, web, and desktop applications. It is the main programming language for developing Flutter apps. In this text, we'll cover the Dart basics that are fundamental to app development using Flutter.

1. Variables and Data Types

In Dart, a variable is a name given to a memory location that stores values. In Dart, you can declare a variable using the 'var' keyword. For example, 'var name = 'John';' declares a variable called 'name' and assigns the value 'John' to it.

Dart supports various data types such as numbers (integers and decimals), strings (sequences of characters), Booleans (true or false), lists (ordered collection of items), and maps (collection of key-value pairs).< /p>

2. Operators

Dart supports a variety of operators like arithmetic operators (+, -, *, /, % for addition, subtraction, multiplication, division and modulus respectively), comparison operators (==, !=, >, <, > =, <= for equal, not equal, greater than, less than, greater than or equal, less than or equal respectively) and logical operators (&&, ||, ! for AND, OR, NOT respectively).

3. Flow Control

Flow control in Dart is done using various flow control structures like if-else, for loop, while loop, do-while loop, switch-case, etc. These structures allow you to control the flow of program execution based on certain conditions or loops.

4. Functions

A Dart function is a block of code that performs a specific task. A function can take some arguments and return a value. Functions in Dart are defined using the 'void' keyword. For example, 'void greet() { print('Hello, World!'); }' defines a function called 'greet' that prints 'Hello, World!' when called.

5. Classes and Objects

Dart is an object-oriented language, which means that it supports the concept of classes and objects. A class is a template for creating objects. An object is an instance of a class. A class in Dart is defined using the 'class' keyword. For example, 'class Person { String name; intage; }' defines a class called 'Person' with two properties 'name' and 'age'.

6. Inheritance

Inheritance is an important feature of object-oriented programming that allows a class to inherit properties and methods from another class. In Dart, inheritance is accomplished using the 'extends' keyword. For example, 'class Employee extends Person { String department; }' defines a class called 'Employee' that inherits the class 'Person' and adds a new property 'department'.

7. Mixins

Mixins is a Dart feature that lets you reuse a class's code across multiple class hierarchies. In Dart, mixins are defined using the 'mixin' keyword and can be used in a class using the 'with' keyword. For example, 'mixin Walk { void walk() { print('Walking...'); } } class Person with Walk { }' defines a mixin called 'Walk' and a class 'Person' that uses the mixin 'Walk'.

These are the basic Dart concepts you need to start developing apps using Flutter. However, Dart is a powerful and flexible programming language that supports many other advanced features that can be useful when developing more complex applications.

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193.1. Dart Basics: Introduction to Dart