Switch Statement in Dart

What is Switch?

The switch statement matches a value against a list of case patterns and executes the matching block. It is cleaner than a long chain of else if when comparing one variable against many fixed values.

Syntax

switch (expression) {
  case value1:
    // code
    break;
  case value2:
    // code
    break;
  default:
    // runs if no case matches
}

Example

void main() {
  String day = 'Monday';

  switch (day) {
    case 'Monday':
      print('Start of the work week!');
      break;
    case 'Friday':
      print('Almost the weekend!');
      break;
    case 'Saturday':
    case 'Sunday':
      print('It is the weekend!');
      break;
    default:
      print('A regular weekday.');
  }

  int statusCode = 404;
  switch (statusCode) {
    case 200: print('OK'); break;
    case 201: print('Created'); break;
    case 404: print('Not Found'); break;
    case 500: print('Server Error'); break;
    default:  print('Unknown status');
  }
}

Start of the work week!
Not Found

Switch Expressions (Dart 3)

Dart 3 introduced switch expressions — a concise inline form that returns a value:

String result = switch (statusCode) {
  200 => 'OK',
  404 => 'Not Found',
  500 => 'Server Error',
  _ => 'Unknown',
};
print(result);

⚠️ Common Mistakes

• Forgetting break — without it, execution falls through to the next case.
• Using a non-constant expression in a case value.

🧠 Quiz

Summary

The switch statement matches a value against constant cases and executes the first match. Always use break to prevent fall-through. Dart 3 adds switch expressions for inline, concise value switching using =>.