field_initializer_redirecting_constructor

The redirecting constructor can't have a field initializer.

The analyzer produces this diagnostic when a redirecting constructor initializes a field in the object. This isn't allowed because the instance that has the field hasn't been created at the point at which it should be initialized.

The following code produces this diagnostic because the constructor C.zero, which redirects to the constructor C, has an initializing formal parameter that initializes the field f:

class C {
  int f;

  C(this.f);

  C.zero(this.f) : this(f);
}

The following code produces this diagnostic because the constructor C.zero, which redirects to the constructor C, has an initializer that initializes the field f:

class C {
  int f;

  C(this.f);

  C.zero() : f = 0, this(1);
}

If the initialization is done by an initializing formal parameter, then use a normal parameter:

class C {
  int f;

  C(this.f);

  C.zero(int f) : this(f);
}

If the initialization is done in an initializer, then remove the initializer:

class C {
  int f;

  C(this.f);

  C.zero() : this(0);
}

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.