What does a class with a method named ._() mean in Dart/Flutter?

In Dart, a class with a method named ._() typically indicates that the method is intended to be private and should not be accessed outside the class or its library. The use of an underscore (_) before the method name is a convention in Dart to mark it as private.

In Dart, identifiers that start with an underscore (_) are considered private, meaning that they can only be accessed from within the same library. This allows developers to hide implementation details and prevent unintentional access to certain methods or variables from outside the class or library.

For example:

class MyClass {
  int _privateValue = 42;

  void _privateMethod() {
    print('This is a private method.');
  }

  void publicMethod() {
    _privateMethod(); // OK, can access the private method within the same class.
  }
}

void main() {
  var obj = MyClass();
  obj.publicMethod();

  // The following lines would cause a compilation error:
  // obj._privateValue; // Cannot access private variable outside the class.
  // obj._privateMethod(); // Cannot access private method outside the class.
}

In this example, the _privateValue and _privateMethod in the MyClass class are private and can only be accessed within the class itself. The publicMethod can call _privateMethod since it’s within the same class, but the main function cannot access _privateValue or _privateMethod due to their private nature.

Using private methods and variables with the underscore prefix is a helpful practice for encapsulation and information hiding, which is an essential concept in object-oriented programming. It allows you to define a clear public interface for your class while keeping the implementation details hidden and protected from external interference.

error: Content is protected !!