Gain insights into Dart's object-oriented features, explore extensions, enums, mixins, and asynchronous programming. Discover hands-on code practice to confidently apply Dart in your projects.

dart.tar.gz

dart2_7

Dart is a fully object-oriented, class-based, simple, and clean language. Google’s popular mobile framework, Flutter uses Dart language to implement high-quality native applications, so it’s recommended that you understand Flutter before beginning this course.

In this course, you will dive deep into Dart 2 language features while using interactive hands-on code playgrounds. This course will help you become confident with Dart extensions, enums, mixins, generics, libraries, asynchronous programming, class variables, callable classes, and generator functions.

By the end of this course, you will have a strong understanding of Dart principles, and you’ll be ready to start using this powerful language in your own projects.

Developing Web Applications with Dart

# Introduction

The variables and methods of a class are shared across all instances of the class. They are not called on any specific object instance of the class.  

In the Dart language, there are two ways to implement such variables and methods.
1. Using the `static` keyword
2. Without the `static` keyword

The class-level variable(s) is useful to declare constants and implement a class-wide state. Generally, utility classes use class variables and methods to provide quick and easy access to methods and constants.


# With the `static` keyword

The `static` keyword is used to declare class level variables and methods. 

The class methods can be called from other classes using the class names they are defined in.

Let's take an example of a string utility class called `StringUtils`. This class contains a convenience method called `reverse(String str)` to reverse the given string. This utility class has a constant `dart` which is inferred to contain a string value of "oh dart."

```dart
class StringUtils {
  static const dart = "oh dart";

  static String reverse(String str) {
    return String.fromCharCodes(str.runes.toList().reversed);
  }
}
```

**Note:** If you are interested in learning about `runes` used in code above to reverse the string, check out [my article](https://ptyagicodecamp.github.io/the-runes-property.html) on Runes.


## Using a Class variable
Let's reiterate the facts about class variables:
* Static variables are not initialized until they are used.
* They are useful for representing class state and constants.
* Constants names are declared using the [lowerCamelCase](https://dart.dev/guides/language/effective-dart/style#identifiers) convention.
* The class-level variable can be accessed using the class name.

In the code below, `StringUtils` is needed to access constant `dart`.

This lesson covers Dart's Class level variable(s) and method(s).

Introduction

Dart Extensions

Dart Enums

Dart Mixins

Dart Generics

Dart Libraries

Asynchronous Programming In Dart

Miscellaneous

Next Steps

Class Variables & Methods

Introduction

With the `static` keyword

Class Variables & Methods

Introduction

With the static keyword

With the `static` keyword