Java How to Program (early objects), 9/e

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 9) and public static method getCount (lines 36–39). The static variable count is initialized to zero in line 9. If a static variable is not initialized, the compiler assigns it a default value—in this case 0, the default value for type int. Variable count maintains a count of the number of objects of class Employee that have been created so far.

When Employee objects exist, variable count can be used in any method of an Employee object—this example increments count in the constructor (line 18). The public

Fig. 8.12