Episode 4: Exploring Dart: Comments

Season 2: Exploring Dart

Dart, an object-oriented programming language, is seeing a surge in popularity due to its efficiency, conciseness, and ease of learning. As with many languages, comments are a fundamental part of coding in Dart. In this article, we'll explore the various types of comments in Dart: single-line comments, multi-line comments, and documentation comments.

Single-line Comments

A single-line comment in Dart begins with two forward slashes //. Everything that comes after these slashes, on the same line, is ignored by the Dart compiler.

Example:

void main() {
  // TODO: refactor into an AbstractLlamaGreetingFactory?
  print('Welcome to my Llama farm!');
}

Here, the single-line comment is a handy reminder to refactor a piece of code in the future. This comment doesn't interfere with the execution of the code, and the program will print 'Welcome to my Llama farm!' when run.

Multi-line Comments

For situations where a comment spans several lines, Dart provides multi-line comments that begin with /* and end with */. Every character between these symbols is ignored by the Dart compiler. This is often used for temporarily disabling chunks of code or adding extended descriptions.

Example:

void main() {
  /*
   * This is a lot of work. Consider raising chickens.
   * 
   Llama larry = Llama();
   larry.feed();
   larry.exercise();
   larry.clean();
   */
}

The block of code inside the multi-line comment is disregarded by the compiler, making it easy to comment out large parts of code for testing or debugging.

Documentation Comments

Dart takes commenting a step further with documentation comments, which can be used to generate documentation for your classes, methods, and variables. These comments begin with /// for single-line, or /** for multi-line comments. They can also include Markdown formatting.

Example:

/// A domesticated South American camelid (Lama glama).
///
/// Andean cultures have used llamas as meat and pack
/// animals since pre-Hispanic times.
///
/// Just like any other animal, llamas need to eat,
/// so don't forget to [feed] them some [Food].
class Llama {
  String? name;

  /// Feeds your llama [food].
  ///
  /// The typical llama eats one bale of hay per week.
  void feed(Food food) {
    // ...
  }

  /// Exercises your llama with an [activity] for
  /// [timeLimit] minutes.
  void exercise(Activity activity, int timeLimit) {
    // ...
  }
}

Documentation comments enable developers to add rich, linked documentation to their code. Here, [feed] will become a link to the documentation for the feed method, and [Food] a link to the Food class in the generated documentation.

Conclusion

Comments in Dart provide a versatile and robust way to make code more readable, maintainable, and understandable. From single-line reminders to multi-line explanations to full-fledged documentation, Dart supports it all.

Remember, comments are not just for your future self; they are essential for anyone else who reads your code. Good commenting practice helps in team collaboration, easy debugging, and code quality.

Dive into Dart and make the best use of these commenting capabilities. Whether you're building a simple script or a complex application, comments will be your allies in producing clean, clear, and efficient code. Happy coding!