Android™ How to Program, Second Edition

G.4.3. Creating a CommissionEmployee–BasePlusCommissionEmployee Inheritance Hierarchy

Now we redeclare class BasePlusCommissionEmployee (Fig. G.8) to extend class CommissionEmployee (Fig. G.4). A BasePlusCommissionEmployee object is a CommissionEmployee, because inheritance passes on class CommissionEmployee’s capabilities. Class BasePlusCommissionEmployee also has instance variable baseSalary (Fig. G.8, line 6). Keyword extends (line 4) indicates inheritance. BasePlusCommissionEmployee inherits CommissionEmployee’s instance variables and methods, but only the superclass’s public and protected members are directly accessible in the subclass. The CommissionEmployee constructor is not inherited. So, the public BasePlusCommissionEmployee services ...