Java™ How To Program (Early Objects), Tenth Edition

Tracking the Number of Employee Objects That Have Been Created

Our next program declares two classes—Employee (Fig. 8.12) and EmployeeTest (Fig. 8.13). Class Employee declares private static variable count (Fig. 8.12, line 7) and public static method getCount (lines 36–39). The static variable count maintains a count of the number of objects of class Employee that have been created so far. This class variable is initialized to zero in line 7. If a static variable is not initialized, the compiler assigns it a default value—in this case 0, the default value for type int.

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 1   // Fig. 8.12: Employee.java 2   // static variable used to maintain a count of the number of 3   // Employee objects in memory. 4  5   public ...