However, only ordinary method calls can be polymorphic;
For example: if you access a field directly , that access will be resolved at complie time;
public class public_field_ { public static void main(String[] args) { Super sup = new Sub(); /** * output: 0; */ System.out.println(sup.field); /** * output: 1; */ sup.getField(); }}class Super { public int field =0; public void getField() { System.out.println(field); }}class Sub extends Super { public int field = 1; public void getField() { System.out.println(field); } public void getSuperField() { System.out.println(super.field); }}
in this example , diffrent storage is allocated for Super.field and Sub.field. Thus ，Sub actually contains two fields called field;