Java Reference
In-Depth Information
Display 6.5
Partially Filled Array Class
(part 2 of 4)
30
maxNumberElements = arraySize;
31
a =
new double
[maxNumberElements];
32
numberUsed = 0;
33
}
34
PartiallyFilledArray(PartiallyFilledArray original)
35
{
36
if
(original ==
null
)
37
{
38
System.out.println("Fatal Error: aborting program.");
39
System.exit(0);
40
}
Note that the instance variable
a
is a copy of
original.a
. The
following would not be correct:
a = original.a;
This point is discussed in the
subsection entitled “Privacy
Leaks with Array Instance
Variables.”
41
maxNumberElements =
42
original.maxNumberElements;
43
numberUsed = original.numberUsed;
44
a =
new double
[maxNumberElements];
45
for
(
int
i = 0; i < numberUsed; i++)
46
a[i] = original.a[i];
47
}
48
/**
49
Adds newElement to the first unused array position.
50
*/
51
public void
add(
double
newElement)
52
{
53
if
(numberUsed >= a.length)
54
{
55
System.out.println("Error: Adding to a full array.");
56
System.exit(0);
57
}
58
else
59
{
60
a[numberUsed] = newElement;
61
numberUsed++;
62
}
63
}
64
public double
getElement(
int
index)
65
{
66
if
(index < 0 || index >= numberUsed)
67
{
68
System.out.println("Error:Illegal or unused index.");
69
System.exit(0);
70
}
71
return
a[index];
72
}
