// polymorphism/FieldAccess.java // (c)2017 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://OnJava8.com for more book information. // 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; @Override 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 */