Object-Oriented Design - Java Software Solutions: Foundations of Program Design - page 340

LISTING 7.15 continued

After changing the values:
f1 f2 f3
999 888 777

After calling changeValues:
a1 a2 a3
111 888 333

Listing 7.16 shows the ParameterModifier class, and Listing 7.17 shows the
Num class. Inside the changeValues method, a modification is made to each of the
three formal parameters: the integer parameter is set to a different value, the value
stored in the first Num parameter is changed using its setValue method, and a new

LISTING 7.16

//********************************************************************
// ParameterModifier.java Author: Lewis/Loftus
//
// Demonstrates the effects of changing parameter values.
//********************************************************************

public class ParameterModifier
{
//-----------------------------------------------------------------
// Modifies the parameters, printing their values before and
// after making the changes.
//-----------------------------------------------------------------
public void changeValues ( int f1, Num f2, Num f3)
{
System.out.println ("Before changing the values:");
System.out.println ("f1\tf2\tf3");
System.out.println (f1 + "\t" + f2 + "\t" + f3 + "\n");

f1 = 999;
f2.setValue(888);
f3 = new Num (777);

System.out.println ("After changing the values:");
System.out.println ("f1\tf2\tf3");
System.out.println (f1 + "\t" + f2 + "\t" + f3 + "\n");
}
}