Programming and Problem Solving with Java

CASE STUDY

136

gives 5.16 as its result. Here is the algorithmic solution:

The method to return the name just calls the Namemethod that provides the name in

the necessary format.

Because the pay was computed and stored when the employee object was instanti-

ated, we return the field value.

The total is updated by each instantiation, so again we can just return the field value.

That’s all there is to the employee class responsibility algorithms. As you can see,

most of the methods are trivial in their design. This simplicity is a common characteris-

tic of object-oriented problem solutions. To hide the implementation details in a

consistent manner, we turn accesses to internal fields into value-returning methods.

Software engineers refer to such methods as observers, and we will have more to say

about their role in a later chapter. Now, let’s look at the code for the Employeeclass,

which we store in a file called Employee.java.

totalPay value-returning class method

returntotal

pay value-returning instance method

returnwages

name value-returning instance method

returnmyName in last, first, MI format

Employee Constructor

Parameters: first, last, middle names, all String; payrate, double

Declare a BufferedReader in

Create a new Name, myName, using first, last, middle

Copy payrate parameter into rate field

Instantiate in using System.in

Prompt for hours worked, using myName firstLast format

Get hours worked from in, and convert to double, storing in hours field

Compute wages and round to cents

Add wages to total

Class Fields

Name myName

double rate

double hours

double wages

static double total