In Dart, there are several ways to comment code:

1. **Single-line comments**: Comments starting with double slashes `//` only comment out the content following them until the end of the line.
   ```dart
   // This is a single-line comment
   int a = 5;
   ```

2. **Multi-line comments**: Use `/* ... */` to comment multiple lines. This comment spans multiple lines until it encounters the closing `*/`.
   ```dart
   /* This is a
      multi-line comment */
   int b = 10;
   ```

3. **Documentation comments**: Use triple slashes `///` or `/** */` for documentation comments, typically used to generate API documentation.
   ```dart
   /// This is a documentation comment
   /// Used to describe the functionality of the function below
   void myFunction() {
     // Function implementation
   }
   ```

Using these comment types helps other readers understand the code's functionality and facilitates future maintenance and updates.

How to Comment Code in Dart?