A small question concerning super

[willemjav]

A small question concerning super
Here is a code sample from the Think in Java book
why is sup.getField one and not zero (see code all the way down)

It probably boils down to the difference of
Super s = new Sub();
Super s = new Super();
right?

//: polymorphism/FieldAccess.java 
// Direct field access is determined at compile time. 
 
class Super { 
  public int field = 0; 
  public int getField() { return field; } 
} 
 
class Sub extends Super { 
  public int field = 1; 
  public int getField() { return field; } 
  public int getSuperField() { return super.field; } 
} 
 
public class FieldAccess { 
  public static void main(String[] args) { 
    Super sup = new Sub(); // Upcast 
    System.out.println("sup.field = " + sup.field + 
      ", sup.getField() = " + sup.getField()); 
    Sub sub = new Sub(); 
    System.out.println("sub.field = " + 
      sub.field + ", sub.getField() = " + 
      sub.getField() + 
      ", sub.getSuperField() = " + 
      sub.getSuperField()); 
  } 
} /* Output: 
sup.field = 0, sup.getField() = 1
sub.field = 1, sub.getField() = 1, sub.getSuperField() = 0 
*///:~

[KevinWorkman]

Why do you think it should be 0?

The instance is of Sub type. The Sub getField() method returns the field value of the Sub class. That value is 1.

[willemjav]

yes i see that now
i got confused by:
Super sup = new Sub(); // Upcast

thanks