Java Reference
In-Depth Information
Display 7.3
The Derived Class
HourlyEmployee
(part 1 of 3)
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/**
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Class Invariant: All objects have a name string, hire date, nonnegative
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wage rate, and nonnegative number of hours worked. A name string of
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"No name" indicates no real name specified yet. A hire date of January 1, 1000
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indicates no real hire date specified yet.
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*/
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public class
HourlyEmployee
extends
Employee
8{
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It will take the rest of Section
7.1 to explain this class
definition.
private double
wageRate;
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private double
hours;
//for the month
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public
HourlyEmployee()
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{
If this line is omitted, Java will still invoke
the no-argument constructor for the
base class.
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super
();
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wageRate = 0;
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hours = 0;
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}
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/**
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Precondition: Neither theName nor theDate is null;
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theWageRate and theHours are nonnegative.
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*/
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public
HourlyEmployee(String theName, Date theDate,
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double
theWageRate,
double
theHours)
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{
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super
(theName, theDate);
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if
((theWageRate >= 0) && (theHours >= 0))
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{
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wageRate = theWageRate;
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hours = theHours;
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}
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else
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{
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System.out.println(
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"Fatal Error: creating an illegal hourly employee.");
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System.exit(0);
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}
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}
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public
HourlyEmployee(HourlyEmployee originalObject)
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{
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super
(originalObject);
An object of the class
HourlyEmployee
is also an
instance of the class
Employee
.
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wageRate = originalObject.wageRate;
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hours = originalObject.hours;
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}
(continued)
