Dart Language Tour

Dart Language Tour

Dart is a modern, object-oriented programming language that is developed and maintained by Google. It is designed to be efficient, scalable, and flexible, with a strong focus on web and mobile application development. With its clean syntax and powerful features, Dart has gained popularity among developers looking for a versatile language to build high-performance applications.

Basics

Dart is a statically typed language, which means that variable types are checked at compile-time. This improves code quality and can help catch errors early in the development process. Let's explore some of the key concepts in Dart.

Variables

In Dart, variables are declared using the `var` keyword. Dart automatically infers the type based on the assigned value. For example:

```dart var firstName = 'John'; var age = 30; ```

Variables can also be explicitly typed using the type annotations. For instance:

```dart String lastName = 'Doe'; int numberOfChildren = 2; ```

Functions

Functions are an essential building block of any programming language. Dart provides various ways to define and use functions, including anonymous functions and lambda expressions. Here's an example of a simple function in Dart:

```dart void greet() {

 print('Hello, World!');

} ```

Dart also supports named and optional parameters, allowing developers to create flexible and reusable functions. Let's see an example:

```dart void greet({String name, String greeting = 'Hello'}) {

 print('$greeting, $name!');

}

greet(name: 'John'); greet(name: 'Jane', greeting: 'Hi'); ```

Control Flow

Dart includes familiar control flow structures like `if-else`, `for` and `while` loops, and `switch` statements. These structures provide developers with the ability to make decisions and repeat code blocks based on specific conditions. Here's an example using an `if-else` statement:

```dart int age = 18;

if (age >= 18) {

 print('You are eligible to vote.');

} else {

 print('You are too young to vote.');

} ```

Collections

Dart offers a variety of collection types, including lists, sets, and maps. These collections provide powerful ways to store, access, and manipulate data. Let's take a look at a few examples:

1. 1. 1. 1. 1. Lists

```dart var numbers = [1, 2, 3, 4, 5]; numbers.add(6); numbers.removeAt(1); ```

1. 1. 1. 1. 1. Sets

```dart var fruits = {'apple', 'banana', 'orange'}; fruits.add('kiwi'); fruits.remove('banana'); ```

1. 1. 1. 1. 1. Maps

```dart var person = {

 'name': 'John',
 'age': 30,

}; person['name'] = 'Jane'; person.remove('age'); ```

Classes and Objects

Dart is an object-oriented language, which means it supports classes and objects. Classes serve as blueprints for creating objects with specific properties and behaviors. Here's an example of a simple class in Dart:

```dart class Person {

 String name;
 int age;

 Person(this.name, this.age);

 void sayHello() {
   print('Hello, my name is $name.');
 }

}

var john = Person('John', 30); john.sayHello(); ```

With Dart's support for inheritance, polymorphism, and interfaces, developers can create complex object hierarchies and achieve code reuse and modularity.

Asynchronous Programming

Dart provides excellent support for asynchronous programming, making it easier to write efficient and responsive applications. Asynchronous programming allows tasks to run concurrently, improving performance and responsiveness. Dart accomplishes this using the `async` and `await` keywords, along with the `Future` and `Stream` classes. Here's an example of using `async` and `await`:

```dart Future<String> fetchData() async {

 await Future.delayed(Duration(seconds: 2));
 return 'Data loaded successfully!';

}

void main() async {

 print('Fetching data...');
 print(await fetchData());

} ```

Dart's asynchronous programming model ensures that applications can perform non-blocking operations such as network requests or file I/O without freezing the user interface.

Conclusion

This comprehensive Dart language tour introduced you to the basics of Dart programming. We covered variables, functions, control flow, collections, classes and objects, and asynchronous programming. Now that you have a solid understanding of the Dart language, you can explore more advanced topics and dive deeper into specific aspects of Dart development.

For more information, check out the following articles on our wiki:

• Control Structures
• Lists in Dart
• Sets in Dart
• Maps in Dart
• Classes and Objects in Dart
• Asynchronous Programming

Happy coding with Dart!