return_in_generative_constructor

Constructors can't return values.

The analyzer produces this diagnostic when a generative constructor contains a return statement that specifies a value to be returned. Generative constructors always return the object that was created, and therefore can't return a different object.

The following code produces this diagnostic because the return statement has an expression:

class C {
  C() {
    return this;
  }
}

If the constructor should create a new instance, then remove either the return statement or the expression:

class C {
  C();
}

If the constructor shouldn't create a new instance, then convert it to be a factory constructor:

class C {
  factory C() {
    return _instance;
  }

  static C _instance = C._();

  C._();
}

Unless stated otherwise, the documentation on this site reflects Dart 3.7.3. Page last updated on 2025-05-08. View source or report an issue.