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

# Extension Operators

Dart provides support for operators in addition to methods that we explored in the [last lesson](https://www.educative.io/pageeditor/5726865580883968/6427715525672960/5509829238980608). In this lesson, we will add two extension operators: `^` and `-` on the `List` type. This list of prices is similar to the last example.

## Example #1

Let's define an operator extension for `^` operator. We can assume this operator increases the price by the `n` times, where `n` is the argument passed into it.

**Defining:**

The `operator` keyword is used to declare an extension of the type operator and is followed by the operator sign itself. In the following example, the current (`this`) list is iterated over to multiply each item by `n,` and the updated list is returned.

```dart
extension<T> on List<T> {
  //Extension Operator: Hike up the price by n
  List<num> operator ^(int n) =>
    this.map((item) => num.parse("${item}") * n).toList();

}
```

**Using:**

The operator `^` is applied to the list `prices`. The operator `^` multiplies each item in `prices` by 3 and returns. The updated list is printed on the console using the `print()` method.

```dart
void main() {
  //List of prices
  List prices = [1, 1.99, 4];

  print("\nPrice listing after hiking up prices 3x of the original value");

  //argument is passed after the operator sign
  print(prices ^ 3);
}
```

**Output:**
The original list items' values are updated to 3 times.
```notepad
Price listing after hiking up prices 3x of the original value
[3, 5.97, 12]
```



Introduction

Dart Extensions

Dart Enums

Dart Mixins

Dart Generics

Dart Libraries

Asynchronous Programming In Dart

Miscellaneous

Next Steps

Extension Operators

Extension Operators