php initialize a class static variable with another static variable of another class

Question

For the following scenario, it didn't work for me. Is there a way to fix it?

class A {
  public static V_A = 'setting_a';
  ...
}

class B {
  public static V_B = A::$V_A;
}

Answer 1

As an answer to my own question - I needed up yanked the static variable V_B in class B, introduced a static function to return the value of A::$V_A, and replace B::$V_B with the function everywhere the static variable is referenced. Essentially, it's what @Abkik suggested.