Understanding inheritance of class variables

Question

I\'m building a Challenge24Solver class in Java. The logic itself works and finds the solutions as would be expected (with an arbitrary number of arguments). A

Answer 1

Static variables are referenced via the class. You have defined operator as being of type Operation, so operator.token refers to Operation.token.

I recommend using a getter for this purpose:

abstract Operation { \\ Basic operation class
  abstract public double operate (double x, double y);
  abstract public String getToken();
}

class AddOp extends Operation {
  public double operate (double x, double y) {
    return x+y;
  }
  public String getToken() {
      return "+";
  }
}